body duringmenstrual cycle
is one of the simplest and most common methods for determining the periodovulation
and thus is a useful diagnostic criterion. Temperature data, which in clinical practice is calledbasal temperature
, are usually entered into a special table in such a way as to form a graph, based on the fluctuations of which one can judge the time of ovulation and a number of other indicators of female reproductive function. Since body temperature is an indicator that is largely determined by the hormonal background, changes in the level of sex hormones during the menstrual cycle significantly affect the basal temperature values.
Ovulation is one of the key moments of the menstrual cycle and is the process of the release of a mature egg from the follicle intoovaries
... This period is the most favorable forconceiving a child
, since the fusion of the egg withsperm
can occur only within a day after ovulation (the time during which the egg retains its viability
). Usually ovulation occurs on the 13th to 15th day of the menstrual cycle. Earlier or later ovulation, as well as its absence, may indicate some pathology of the reproductive system or other organs.
For many decades, basal body temperature charts have been one of the most common and recommended methods for tracking the ovulatory phase of the menstrual cycle in childless couples who have difficulty conceiving. In addition, the symptothermal method of contraception is based on tracking basal temperature and a number of other parameters (calculating the day of ovulation based on the beginning and duration of the menstrual cycle, as well as on changes in the viscosity of the mucus of the cervical canal
). It should be noted that with the correct use of this method of contraception and with abstinence during the appropriate periods of the menstrual cycle, protection against unwantedpregnancy
reaches a level comparable to oral contraceptives.
It should be understood that fluctuations in basal temperature directly reflect the moment of ovulation and the next phase of the menstrual cycle, but in no way predict it. In addition, rectal measurement of body temperature requires a woman to be very self-disciplined and disciplined, since for correct measurements they must be taken at the same time, in the morning, without getting out of bed. Any changes in the process of measuring temperature, as well as sexual intercourse, playing sports, drinking alcohol, psychoemotionalstress
, systemic and intestinal, bacterial and viralinfections
can significantly affect the measurement results. For this reason, it is now recommended to use other methods of examination and diagnosis, which are much more sensitive and much less susceptible to random fluctuations. Nevertheless, as one of the indicative indicators, as well as a cheap and affordable diagnostic method, basal temperature measurement is practiced by many women and married couples.
What hormones and body structures cause temperature changes during the cycle?
The menstrual cycle occurs as a result of the complex coordinated activity of a number of brain structures, endocrine glands and internal genital organs. From a medical point of view, the menstrual cycle is correctly called the hypothalamic-pituitary-ovarian-uterine cycle, which reflects the structures and organs involved in this process.
Speaking about hormones and regulatory brain structures in gynecological practice, first of all, it is necessary to consider the hypothalamus and its effects on the genitals and on the female body as a whole. The hypothalamus is a nerve center in the midbrain that regulates rhythmic (cyclical
) body functions. This process is largely autonomous and automatic, but it also partially depends on higher nervous activity, that is, on the work of the cerebral cortex (thought process and emotions
). Violations of general physical health, emotional failures, as well as malfunctions of the endocrine glands can cause changes in the normal rhythmic activity of the hypothalamus.
The hypothalamus is a structure responsible for daily fluctuations in body temperature, which in the morning hours can be one to two degrees lower than in the evening. It is quite obvious that these fluctuations are caused by changes in the state of rest and increased metabolism and therefore do not reflect the true basal body temperature.
The stimulating activity of the hypothalamus on the pituitary gland, mediated by nerve impulses and, to a greater extent, hormones, is the basis of the menstrual cycle. Released stimulating and inhibiting substances (liberins and statins
) affect the pituitary gland, thereby stimulating or inhibiting the synthesis of other important hormones.The activity of the hypothalamus is regulated by the following mechanisms:
- Feedback principle. The feedback principle is one of the main mechanisms of hormonal regulation in the human body. It is based on the recognition of specific hormones or other substances by the responsible structures and in the correction of their amount and synthesis intensity in accordance with the concentration in the blood plasma ( or in organ tissues ). In other words, a low content of a certain hormone has a stimulating effect on the gland, while an excess of this hormone inhibits the synthetic activity of this gland. The activity of the hypothalamus depends on the concentration of sex hormones, pituitary hormones, as well as on the concentration of its own hormones ( liberins and statins ).
- Regulation by higher nervous activity. Emotional tension and stress affect the function of the hypothalamus. This happens both due to the influence of impulses emanating from the cerebral cortex, and due to the influence of impulses emanating from other brain structures ( which are located in close proximity to the nuclei of the hypothalamus ). This influence is especially noticeable in the study of the menstrual cycle, the rhythm of which can be disturbed against the background of strong experiences, after a change in climate or a change in the time zone, as well as as a result of excessive anxiety or tension. It should be noted that under the influence of higher nervous activity in women who work for a long time in the same team and communicate closely, the effect of synchronization of menstrual cycles can be observed.
The hypothalamus produces several types of regulatory hormones, each of which affects specific endocrine glands and target organs. The main hormone affecting the menstrual cycle is gonadoliberin, which can stimulate the pituitary gland and enhance the synthesis of other important hormones. This substance is produced regularly and in small quantities. Its concentration depends on the level of sex hormones and a number of other factors, therefore it is different in different phases of the menstrual cycle.
The pituitary gland is probably the main endocrine gland, as it is responsible for the production of most of the regulatory hormones. The pituitary gland is located in the lower part of the brain, in a special bone formation called the Turkish saddle. The function of this gland is closely related to the hypothalamus.The pituitary gland affects reproductive function through the following hormones:
- Follicle-stimulating hormone. Follicle-stimulating hormone ( FSH ) begins to be synthesized in large quantities by the end of the menstrual cycle and is a substance that activates the growth and function of a new primary follicle, from which an egg cell ready for fertilization will subsequently emerge. The production of this hormone gradually increases until the moment of ovulation ( oocyte release from the follicle ), after which its concentration decreases sharply. Nevertheless, it should be understood that the synthesis of FSH during the physiological menstrual cycle never stops, but only its concentration and ratio with other sex hormones change.
- Luteinizing hormone. Luteinizing hormone ( LH ) is synthesized in insignificant amounts during 12-13 days of the cycle, and it is believed that it is responsible for the rupture of the follicle and the release of the egg, that is, for ovulation. After ovulation, the concentration of this hormone increases. Under its action, the cells of the ruptured follicle turn into the so-called yellow body, which synthesizes progesterone ( female sex hormone ). It is progesterone that is responsible for a slight increase in body temperature in the second phase of the menstrual cycle ( that is, after ovulation ).
It must be understood that the production of pituitary hormones is a fickle process, the intensity of which depends on many parameters. The function of this organ, like that of the pituitary gland, is controlled by a feedback mechanism (changes in the level of FSH, LH, sex hormones
) and through the stimulating or inhibitory effect of hypothalamic hormones.
The ovaries are the main female sex glands, which, in addition to producing hormones, are the site of the maturation of female germ cells. It should be noted that female sex hormones in their chemical structure are extremely close to male sex hormones and, moreover,estrogens
are the product of a number of chemical transformations of androgens (male sex hormones
).In the ovaries, the following sex hormones are synthesized:
In addition to these hormones, a rather large number of substances with regulatory and hormonal activity are synthesized in the ovaries, which are necessary for the emergence and development of a normal menstrual cycle, as well as for the full activity of the female reproductive system.
It should be noted that it is the fluctuations of female sex hormones produced in the ovaries that cause changes in basal temperature during the menstrual cycle. Since these hormones are produced not by the tissues of the entire ovary, but by the cells that form the follicle membrane or its lining, changes in their concentration directly depend on the state of the follicle and the stage of its development. Progesterone, a hormone that is synthesized by the corpus luteum (altered follicle membrane
). Under its influence, there is an increase in temperature by 0.5 - 0.6 degrees, which is observed until the end of the menstrual cycle. It is believed that this is due to its direct effect on sensitive receptors in the hypothalamus, which is the body's thermoregulatory center.
Hormonal and functional changes in the ovaries during the menstrual cycle
In the menstrual cycle, three successive phases are distinguished, each of which is characterized by certain structural and functional changes in the ovaries and other female reproductive organs. It is necessary to understand that in each of the phases the hormonal background is significantly different, which is the main driving force behind this process.The menstrual cycle includes the following phases:
- follicular phase;
- luteal phase.
The follicular phase begins on the first day of menstruation and lasts until ovulation. During this period, one dominant follicle develops in the ovaries, which will subsequently release an egg ready for fertilization. Also, the follicular phase is characterized by the active synthesis of sex hormones and a number of other substances that have a significant effect on female reproductive function. The main hormone of this period is FSH (follicle-stimulating hormone
) produced in the pituitary gland. Under its action, as mentioned above, the dominant follicle develops, which begins to actively produce estrogens, which somewhat reduces the concentration of FSH (feedback mechanism
). In addition, the granular cells of the growing follicle (the layer of cells surrounding the follicle
) produce a number of peptides that have limited hormonal and regulatory activity and are able to block the development of other follicles.
It is necessary to understand that the follicle in its structure resembles a small ball, in the center of which the egg is located, and around it is a protective shell. There is a layer of fluid between this membrane and the egg. The cells that form the follicular membrane have the ability to synthesize female sex hormones. The hormones and other substances produced are partly accumulated in the follicular fluid, and partly absorbed into the blood. By the time of ovulation, the concentration of sex steroid hormones in the follicular fluid significantly exceeds their concentration in the blood. For this reason, after ovulation, there is a short increase in estrogen levels, which is associated with the release of this fluid.
Ovulation occurs around the middle of the menstrual cycle, usually on days 13-14 (subject to a cycle duration of 28 days
). Follicular membrane rupture is usually triggered by an increase in LH (pituitary luteinizing hormone
). This happens under the influence of positive feedback, that is, due to the stimulating effect of estrogens on the hypothalamus and pituitary gland. The concentration of female sex hormones becomes sufficient to trigger this mechanism when the follicle size reaches approximately 15 mm (with ultrasound examination
). An increase in LH levels is observed 34 to 36 hours before ovulation and is a relatively stable predictor of ovulation.
Luteinizing hormone stimulates the synthesis of progesterones and also induces changes in the follicle membrane. In addition, under its action, the processes of cell division and maturation of the egg are completed, which becomes ready for fertilization. Before ovulation, the concentration of estrogens decreases and for a short period of time FSH production increases, which is presumably due to the effect of progesterone on the hypothalamic-pituitary system.
The exact mechanism of follicle rupture is currently not well understood. It is assumed that under the action of progesterone, LH and FSH are producedenzymes
and substances that break down the follicle membrane. Some increase in the pressure of the follicular fluid leads to rupture of the follicle and the release of the egg outside. In addition, this results in the release of sex hormone-rich (primarily progesterone
) follicular fluid. Because of this, there is a significant increase in the concentration of progesterone in the blood immediately after ovulation. Since progesterone has a stimulating effect on the thermoreceptors of the hypothalamus, an increase in body temperature is observed immediately after ovulation.
The luteal phase lasts about two weeks in most women. After ovulation, granulosa cells (follicle membrane cells
) do not dissolve and do not undergo reverse involution, but continue to increase in size and accumulate yellow pigment (called lutein
). Thus, luteinized granulosa cells, in combination with a number of other cells of the follicle membrane, turn into a yellow body - a temporary organ of internal secretion of the female reproductive system, the main function of which is the production of progesterone. Thanks to this, the endometrium is prepared (mucous membrane of the uterus
) to implantation (implantation of a fertilized egg
). The highest progesterone level is observed on the 9-10th day after ovulation, when the maximum number of blood vessels is formed in the corpus luteum, and when its function reaches its peak. It should be understood that due to the increased concentration of progesterone, slightly higher basal temperatures are noted during almost the entire luteal phase.
The function of the corpus luteum decreases towards the end of the luteal phase of the menstrual cycle. This is due to a decrease in LH levels and a gradual increase in FSH levels. However, it should be noted that if fertilization and implantation have occurred, that is, pregnancy has occurred, chorionic gonadotropin (hormone produced by the placenta
) continues to maintain the corpus luteum until the end of pregnancy. This provides physiological protection from another pregnancy until the end of this one. If pregnancy did not occur, the corpus luteum undergoes reverse development and is gradually replaced by connective tissue, forming a white body.
Changes in the organs of the reproductive system during the menstrual cycle
It is necessary to understand that not only the ovaries undergo changes during the menstrual cycle. The most significant changes occur in the uterine cavity, as well as in the cervix and vagina.
The endometrium is the inner lining of the uterus. During the menstrual cycle, the endometrium, under the influence of sex hormones, goes through several developmental phases, thus preparing for the acceptance of an egg during implantation.There are the following phases of endometrial development during the menstrual cycle:
- Proliferative phase. During the proliferative phase, there is a gradual multiplication of endometrial cells, which after menstruation consists of a small layer of basal cells. Under the influence of estrogens, the endometrium thickens, rather long and convoluted glands develop in it, and convoluted vessels are formed.
- Secretory phase. The secretory phase begins immediately after ovulation, when an increased concentration of estrogens and progesterones is present in the blood. In this phase, the division of endometrial cells is inhibited, and they undergo a number of structural changes that form the optimal conditions for implantation of a fertilized egg.
- Menstruation. If pregnancy has not occurred, there is a gradual rejection of the functional layer of the endometrium. In this case, the destruction of a number of convoluted vessels of the mucous layer occurs, which, in combination with the exfoliated cells of the endometrium, forms menstrual flow. Typically, bleeding lasts 5 to 7 days from the start of the menstrual cycle.
A change in the hormonal background affects the cervix and the glands that produce its mucous secretion. Immediately after menstruation, the cervical mucus is quite viscous and scanty. During the follicular phase, under the influence of estrogens, the cervical mucus becomes more transparent and elastic, and its amount increases more than 30 times compared to the initial level. After ovulation, as the level of progesterone increases, the cervical mucus becomes viscous, opaque and scanty again.
These changes in cervical mucus are associated with reproductive function, and specifically with the ability to pass sperm. In the period before and immediately after ovulation, when the chances of getting pregnant are greatest, cervical mucus is the least viscous, which creates minimal resistance for sperm.
Changes in the concentration of estrogens and progesterones also affect the vaginal mucosa. So, under the influence of these hormones, the structure and function of the cells of the vaginal mucosa changes somewhat, due to which the vaginal environment changes.
Indications for measuring basal temperature
Measurement of basal body temperature is a method that allows you to identify the moment of ovulation and makes it possible to indirectly judge the level of certain sex hormones. The data obtained by this method are useful forplanning pregnancy
, as well as if you suspect hormonal disruptions or if there is a pathology of the menstrual cycle.Measurement of rectal temperature should be performed in the following situations:
- When planning a pregnancy. Measuring basal temperature when planning pregnancy allows you to identify the moment of ovulation and, thus, is a way to determine the most appropriate time for conception. In addition, the measurement of rectal body temperature makes it possible to exclude or suggest a number of pathologies of the female reproductive system if conception is impossible.
- As a comprehensive method of contraception. Regular and correct measurement of basal body temperature allows you to track ovulation and thus can be used as a method of contraception. With abstinence from the first day of menstruation until the third day after ovulation, the risk of becoming pregnant is only 0.2 - 0.3% ( with regular intercourse for one year ), which is comparable in reliability to the use of hormonal contraceptives. If, in addition to the temperature method, we simultaneously examine the cervical mucus, which becomes transparent, viscous and abundant on days favorable for conception ( that is, on days on which sexual intercourse should be avoided to prevent unwanted pregnancies ), then the reliability of this method increases slightly. It should be noted that other schemes of protection against unwanted pregnancy based on changes in basal temperature are described in the literature. It must be remembered that measuring rectal temperature is an extremely capricious method that requires strict adherence to the time and study schedule. If measured incorrectly, the data can mislead a woman, therefore this method of contraception cannot be considered extremely reliable.
- When diagnosing pathologies of the menstrual cycle. The basal temperature graph reflects changes in hormone levels and some structural and functional changes in the female reproductive system. Based on the nature of body temperature fluctuations, a number of pathologies of the endocrine glands or reproductive system can be assumed. However, measurement of rectal temperature does not allow confirmation of the preliminary diagnosis, since this requires more sensitive and specific laboratory tests.
Despite the significant development of laboratory diagnostic methods, many doctors still practice and prescribe basal temperature measurement as one of the inexpensive and relatively reliable research methods. The basal temperature graph is of greatest interest to gynecologists, especially in the presence of any disorders from the menstrual cycle or the entire reproductive tract. Also, this chart can be useful for doctors dealing with problemsinfertility
, as well as for endocrinologists (studying endocrine glands
Temperature measurement and recording technique
Basal temperature reflects the body temperature immediately after waking up, at the same time, before the start of any activity. This method involves measuring body temperature by placing a thermometer in the rectum, that is, rectally. Oral measurement (putting a thermometer in your mouth
) or vaginal (placing a thermometer in the vagina
) are also acceptable measurement methods, but they are not the standard for this study.
It should be noted that the body temperature in the oral cavity, in the vaginal cavity and in the rectum is somewhat different (the difference in the norm can reach one degree
). Therefore, if initially the temperature graph was based on one measurement method, the same methodology should be followed until the end of the study.
In most cases, oral measurement of body temperature allows you to accurately judge changes in basal temperature. However, with significant temperature fluctuations or, conversely, with insufficient temperature change, one should proceed to rectal measurement, since this method is the most sensitive.
The measurement can be carried out both with a mercury thermometer and an electronic one. When measuring with a mercury thermometer, you should be extremely careful, since a change in the position of the body or any inaccurate action can cause its breakdown, which threatens serious health consequences, since glass fragments and mercury are extremely dangerous. Measurement with electronic thermometers, which are quite accurate and safe today, is a more acceptable method.
Basal temperature measurement should be carried out after sleep, the duration of which should be at least three hours. This is due to the fact that body temperature fluctuates during the day, and during sleep it reaches a certain basal level, which should be monitored.
The data obtained when measuring the basal body temperature must be entered into a special table, which can be built using a sheet from a regular school notebook in a box. To do this, a graph is built on the sheet, on the vertical axis of which the temperature value is indicated from 36 degrees to 37.5 (sometimes these values need to be adjusted depending on individual characteristics
). The temperature step of the vertical axis should be 0.1 - 0.2 degrees. In other words, a 0.1 degree rise in temperature should correspond to one or two cells, depending on the selected scale. The horizontal axis of the graph represents days and is labeled from 1 to 28 or more depending on the length of the menstrual cycle. In the future, the points showing the temperature are combined using a curved line, which will visually display changes in basal temperature.
Basal body temperature should be entered into the table starting from the first day of the menstrual cycle, that is, from the day the menstrual flow appears. A new table should be started at the end of the menstrual cycle.
As mentioned earlier, basal body temperature measurement is an extremely capricious method that is sensitive to many factors not related to reproductive function.Basal temperature fluctuations can be triggered by the following factors:
- Alcohol consumption. Alcohol consumption affects the data obtained when measuring basal temperature. This is due, firstly, to some metabolic changes and, accordingly, to an increase in the amount of heat produced. Secondly, alcohol affects peripheral blood vessels, causing them to dilate and fill with blood, thereby somewhat altering the normal regulation of body temperature. Thirdly, ethyl alcohol can directly affect the center of thermoregulation and some endocrine glands, which can cause changes in basal temperature. In addition, alcohol can interfere with the correct measurement.
- Little or no sleep. During sleep, physiological and neurological processes change somewhat, some systems are activated and others are inhibited. Lack of sleep significantly affects these processes, which makes the data obtained when measuring basal temperature is incorrect. In addition, short sleep is a factor that increases stress levels, which may also affect the study results.
- Sleep too long. Prolonged sleep for more than twelve hours can also lead to incorrect basal body temperature measurements. This is due, as well as in the absence of sleep, with a change in brain and hormonal activity during the sleep-wake cycle.
- Travel, time zone change. Changing the time zone or traveling can cause some disruption in the functioning of the brain and autonomic nervous system, of which the hypothalamus is a part. As a result, hormonal fluctuations can occur, which can affect the menstrual cycle and basal temperature. In addition, it can cause a direct change in body temperature ( since the hypothalamus is the center of thermoregulation ).
- Infections. In most cases, the infectious and inflammatory process in the body is accompanied by the release of biologically active substances that can change the body temperature by affecting the thermoregulation center. An increase in body temperature in response to infection is a kind of protective mechanism that is aimed at creating unfavorable conditions for the development of pathogenic microorganisms and at creating optimal conditions for the development and operation of one's own immune system. It is quite natural that fluctuations in body temperature that have arisen against the background of an infectious process will not reflect changes in hormonal levels and menstrual function, therefore, during an illness, the measurement of rectal temperature loses its relevance.
- Gynecological diseases. Many gynecological pathologies can cause changes in basal temperature, while not reflecting the processes of ovulation.
- Intestinal disorders. Intestinal dysfunction affects the temperature in the rectum. For this reason, after food poisoning, diarrhea or other manifestations of intestinal disorders, basal temperature measurements can give erroneous data. It should be noted that the change in the research method ( from rectal to vaginal or oral ) will not help, since the temperature of different areas of the body can vary significantly.
- Sexual intercourse. A hollow act on the eve of basal temperature measurement can greatly affect the results. This is due to some hormonal and functional changes.
- Taking medications. Some medicines can cause changes in body temperature. This can be associated with both a violation of the production of a number of biologically active substances and with a direct effect on the center of thermoregulation, and with a change in the synthesis of hormones, as well as with a number of other mechanisms. When taking medication, you should consult with your doctor or pharmacist and clarify how this medication affects basal temperature.
The principle of body temperature change in different phases of the cycle
The normal basal temperature graph is biphasic, that is, in the first half of the cycle (follicular phase
) the temperature is 0.4 - 0.5 degrees lower than in the second half (ovulation and luteal phase
). These temperature changes are associated, as mentioned above, with the level of sex hormones and, first of all, progesterone.
It should be noted that the graph reflecting the basal temperature is a significantly fluctuating curve line. However, fluctuations in this line within one phase of the menstrual cycle rarely exceed 0.1 - 0.2 degrees and are associated with daily temperature differences, as well as some errors in measuring and reading the results.
The normal temperature curve reflects changes in the ovaries associated with the development of the follicle and the egg within the same menstrual cycle. These changes appear as two deviations in the basal temperature graph. The first deviation is observed one to two days before ovulation and represents a slight decrease in body temperature. For almost 30 years, this decrease in temperature has been considered as one of the possible indicators indicating imminent ovulation. However, scientific studies have not confirmed this theory, and a decrease in basal temperature today cannot be considered as a sign of impending ovulation. The second deviation on the temperature curve is more constant and represents a rise in temperature by 0.4 - 0.5 degrees from the previous level. This change in basal temperature reflects the moment of ovulation and is associated with a significant increase in the level of progesterone in the blood. Since further during the entire luteal phase the concentration of progesterone is at a rather high level, the temperature during this stage is also slightly higher.
It should be noted that immediately before the onset of menstruation, there may also be a slight decrease in body temperature, which is associated with a decrease in progesterone levels and a gradual increase in FSH concentration (follicle-stimulating hormone
Thus, the rise in body temperature in the second half of the cycle (biphasic temperature curve
) reflects the process of ovulation. However, in some cases, ovulation can occur without a pronounced rise in body temperature, which significantly limits the possibilities of this method as a way of planning sexual intercourse for conception.
Interpreting the results of the temperature curve
In medical practice, it is customary to distinguish five types of possible temperature curves. The first of them reflects the normal menstrual cycle, while the other four occur in the presence of any pathological abnormalities.The following types of temperature curves are distinguished:
- I type - normal temperature curve;
- II type - estrogen-progesterone deficiency;
- III type - insufficiency of the luteal phase;
- IV type - anovulatory menstrual cycle;
- V type - chaotic temperature curve.
Normal temperature curve
The normal temperature curve is characterized by a slight decrease in body temperature just before ovulation and before the end of the menstrual cycle. Also, a normal graph shows an increase in body temperature of more than 0.4 degrees after ovulation (biphasic temperature curve
). According to modern data, in some women, ovulation can cause an increase in body temperature slightly less than 0.4 degrees.
The duration of the menstrual cycle and, accordingly, the temperature curve is on average 28 days. A cycle is considered normal if it falls within these limits plus or minus one week (that is, 21 - 35 days
Ovulation occurs approximately in the middle of the menstrual cycle, that is, on days 13 to 15. The duration of the luteal phase, that is, the phase when the body temperature is slightly increased, is 12-14 days.
Estrogen-progesterone deficiency is a hormonal imbalance in which, for whatever reason, the level of female sex hormones - estrogen and progesterone - is lowered. With this pathology, multiple violations of the menstrual cycle and reproductive function occur, among which the most significant are the absence of ovulation, infertility, and the absence of menstruation. With less pronounced pathology, ovulation can occur, however, due to a lack of progesterone, the maintenance of pregnancy is impaired and habitual miscarriage andmiscarriages
On the temperature curve, estrogen-progesterone deficiency is manifested by a slight rise in body temperature in the second phase of the menstrual cycle (0.2 - 0.3 degrees
). Such a mild temperature fluctuation occurs due to the fact that, against the background of an insufficient content of estrogen, the development of the follicle is slowed down, and its rupture is difficult, and due to the lack of progesterones, there is no rise in temperature as such.There are the following reasons for estrogen-progesterone deficiency:
- malfunction of the hypothalamic-pituitary system due to stress, infections, and so on;
- increased concentration of male sex hormones ( overproduction by the ovaries or adrenal glands );
- increased concentration of prolactin;
- diseases of the thyroid gland;
- pathology of the corpus luteum, producing progesterone;
- infectious and inflammatory processes in the small pelvis, covering the internal female genital organs.
Luteal phase failure
Insufficiency of the luteal phase is a pathological condition in which, for some reason, in the third phase of the menstrual cycle, there is either a low level of progesterone, or an insufficient response to its stimulating effect.Insufficiency of the luteal phase can be caused by the following reasons:
- Abnormal follicle development. Abnormal follicular development results from inadequate secretion of FSH and LH from the pituitary gland. Lack of FSH leads to a delay in the development of follicular membrane cells and to a low content of estrogen. Since the corpus luteum is a structure that arises on the basis of sufficiently developed granulosa cells of the follicle, the poorly expressed development of the follicle can cause insufficient production of progesterone in the third phase of the menstrual cycle.
- Abnormal luteinization. Low LH levels may be caused by decreased levels of androstenedione, a precursor hormone of estrogen that develops from follicular membrane cells under the influence of FSH. An insufficient amount of substrate leads to a reduced production of estrogen, and subsequently progesterone. In addition, a low concentration of LH creates the prerequisites for inadequate luteinization of granulosa cells, that is, for insufficient development of the corpus luteum.
- Abnormalities in the structure of the uterus. The presence of abnormalities in the structure of the uterus creates conditions for inadequate development of the endometrium and the vasculature of the uterus, even in conditions of normal progesterone levels. As a result, an insufficiency of the secretory phase of the development of the endometrium develops during the menstrual cycle, which negatively affects the entire reproductive function.
- Lowered blood cholesterol. Cholesterol is an organic compound that is necessary for the normal functioning of many internal organs, cell membranes, as well as for the synthesis of a number of important steroid hormones, including female sex hormones. Insufficient intake of cholesterol from food in combination with insufficient production of it by the body ( with liver diseases or other pathologies of internal organs ), leads to insufficient synthesis of sex hormones. It should be noted that excess cholesterol also has a negative effect on human health, as it increases the risk of developing atherosclerosis ( the formation of plaques in the lumen of blood vessels ), which increases the chance of cardiovascular disease.
- luteal phase is shorter than 10 days;
- there is no decrease in temperature before the onset of menstruation;
- follicular phase of normal duration;
- ovulation occurs at normal times;
- ovulation is accompanied by a characteristic and normal increase in basal body temperature.
Anovulatory menstrual cycle
Anovulatory menstrual cycle is a pathological situation in which, due to impaired maturation or follicle development, ovulation does not occur, and the second and third phases of the menstrual cycle do not develop.
Anovulatory menstrual cycle occurs as a result of failures in the hypothalamic-pituitary-ovarian axis. Due to a lack of hormones or due to non-physiological fluctuations in their concentration, a normal follicle stops in its development, which leads to many unpleasant consequences.There are the following options for the anovulatory menstrual cycle:
- Follicle atresia. With follicle atresia, one or more follicles in the ovaries stop in their development, while releasing a small amount of estrogen. However, due to the lack of normal physiological dynamics of development ( no ovulation and corpus luteum stage with progesterone production ), there is a relative predominance of estrogens. Over time, these follicles are reborn, turning into small cystic formations.
- Follicle persistence. Follicle persistence is a situation in which the follicle, due to deficiency of FSH and LH, freezes in its development and does not rupture. At the same time, its synthetic function is preserved, and it continues to produce estrogens. The phase of ovulation and the corpus luteum, as well as with follicle atresia, is absent, which leads to progesterone deficiency.
Thus, with any variant of the anovulatory menstrual cycle, there is an excess of estrogen and an absolute lack of progesterone. Because of this, there is no characteristic transformation of the lining of the uterus and uterine blood vessels, which leads to longer, heavy and irregular menstrual bleeding. It is menstrual irregularities that are one of the most striking symptoms of this pathology. In addition, due to the lack of ovulation, women with this pathology suffer from infertility.The temperature curve shows the following signs of anovulatory menstrual cycle:
- the temperature curve is monotonic, without a typical rise in temperature in the second half of the cycle;
- there is no decrease in body temperature before ovulation and before the onset of menstruation;
- the cycle is irregular, of varying duration.
It should be noted that in some cases, menstrual cycles without ovulation can occur in healthy women. This happens due to age-related changes or against the background of psycho-emotional or physical stress. In most cases, this deviation does not require treatment, since it does not cause any other symptoms, and the next cycle usually develops normally.
Chaotic temperature curve
A chaotic temperature curve is a graph that shows significant temperature fluctuations during a cycle that do not fit into any of the above types. In most cases, such a curve is detected when the rectal temperature is measured incorrectly or in the presence of any other, random factors. It should be noted that with severe estrogen deficiency, a chaotic temperature curve can also be observed.
How does rectal temperature change during pregnancy?
When pregnancy occurs, rectal body temperature remains elevated (36.9 - 37.2
), and its characteristic decrease is not observed. In most cases, the basal temperature rises during ovulation by 0.4 or more degrees. At the same time, this indicator usually decreases before the onset of menstruation, however, with the development of pregnancy, it remains at the same level.
Fluctuations in basal body temperature occur against the background of changes in the hormonal background of the female body and are an indicator that changes depending on the period of the menstrual cycle. Since pregnancy provokes significant changes in the functioning of the woman's body, this process is accompanied by some change in rectal temperature.
Phases of the menstrual cycle and changes in basal body temperature
|Phase of the menstrual cycle||Characteristic||Rectal body temperature|
|Follicular phase||Comes on the day of the onset of menstruation. It is characterized by an increased concentration of estrogen ( one of the types of female sex hormones ) and follicle-stimulating hormone, under the influence of which the dominant follicle develops, that is, one of the eggs is prepared to leave the ovaries. In addition to the development of the egg during this period, the functional layer of the endometrium is detached ( inner lining of the uterus ), followed by its regeneration and development.||36.5 - 36.8 degrees.|
|Ovulation||There is a rupture of the dominant follicle with the release of a mature egg from it, and follicular fluid rich in estrogens is released, which briefly increases their concentration in the blood. Later, for a short time, there is a predominance of luteinizing hormone, under the influence of which the follicle membrane forms the corpus luteum - a temporary organ that synthesizes a large amount of progesterone ( female sex hormone ).||Before ovulation, the temperature can drop to 36.3 - 36.5 degrees, followed by a rise to 36.9 - 37.2 degrees.|
|Luteal phase||Immediately after ovulation, a corpus luteum is formed, producing progesterone - a hormone that is responsible for increasing body temperature and affects the entire female reproductive system, preparing it for fertilization and pregnancy.||36.9 - 37.2 degrees.|
After conception, under the influence of hormones produced by the implanted embryo, the corpus luteum continues to function throughout pregnancy. This allows you to protect the female body from a number of aggressive factors, and also prevents other possible pregnancies until the current one is resolved (since the development of a new egg does not occur
). However, since it is progesterone that is the hormone responsible for the increase in body temperature, it is quite obvious that after the onset of pregnancy, due to the increased concentration of progesterone, the basal body temperature will remain within 36.9 - 37.2 degrees.
A stable increase in basal body temperature by 0.4 - 0.5 degrees, which lasts more than 17 - 18 days and is accompanied by a delay in the onset of menstruation, can often be considered as one of the signs of pregnancy. However, this indicator is extremely unstable, since it depends on a large number of different variables, so it can only be used as one of the indicative tests, but not as a way to definitively confirm pregnancy. Nevertheless, if the basal body temperature does not decrease for such a long time, it is recommended to dopregnancy test
It should be understood that for a correct assessment of the basal temperature, a correct measurement is a prerequisite. The study should be carried out at the same time in the morning, before getting out of bed, with the same thermometer, by placing it in the rectum (or vagina
). The data should be entered into a special table. Short sleep, alcohol consumption, stress, illness and other factors can affect the measurement results.
Is it possible to measure basal temperature during the day or in the evening?
Measurement of basal temperature should be taken in the morning, before getting out of bed and before starting any activity. Measurement of rectal temperature during the day or in the evening is completely incorrect, since many factors affect the body temperature during these hours.
Basal body temperature is an indicator that reflects a person's body temperature at rest, without any external factors. This indicator depends only on the general condition of the body, hormonal levels, as well as on the neuro-emotional component. Since in the vast majority of cases, basal temperature is measured to assess the menstrual cycle and to determine the period of ovulation, the most significant factor determining the temperature is the concentration of sex hormones. Thus, the more variables that affect temperature, the more difficult it is to track hormone fluctuations, and the more inaccurate measurements become.
Measurement of basal body temperature in the afternoon or in the evening is incorrect due to the fact that after the start of daytime activities, the body is exposed to a large number of external and internal factors that, to one degree or another, change the measurement results.The following factors affect the basal temperature:
- Physical activity. Any physical activity affects the basal temperature readings. This is due to the fact that during physical effort, even if it is insignificant, high-energy nutrient molecules are broken down in muscle fibers, which is accompanied by the release of additional temperature. In addition, the contraction of the muscle fiber itself is a process that promotes the release of heat. As a result, the temperature readings differ slightly from the initial, basal level. It should be understood that different intensities of physical activity affect temperature in different ways. For this reason, measuring body temperature before starting any activity is one of the key points that allows you to somewhat standardize this process.
- Food intake. The process of eating changes intestinal motility, affects blood circulation and temperature in the rectum. In most cases, this factor only slightly affects the basal temperature readings, however, eating too spicy or unsuitable food can greatly change the values obtained.
- Alcohol consumption. Alcohol is a substance that by itself can increase the level of heat produced by the body ( when the alcohol molecule breaks down ) and can significantly alter the blood circulation in the vessels, thereby increasing blood flow and altering the readings of rectal or any other body temperature measurement.
- Psycho-emotional stress. The regulation of body temperature is carried out by a number of brain structures that are located in close proximity to the centers responsible for emotions. As a result, any psycho-emotional stress to one degree or another can affect body temperature during the day.
- Daily rhythm. The human body is characterized by functioning in a certain cyclical rhythm. This is explained by the frequency of hormone production and neurovegetative stimulation depending on the time of day ( amount of light ). As a result, the body temperature in the evening is slightly different from that in the afternoon or morning. For this reason, it is not correct to compare temperatures measured at different times of the day.
Thus, when measuring basal temperature during the day, there are too many factors that cannot be taken into account when interpreting the result, but which, one way or another, change body temperature. Therefore, the easiest method to standardize research is to conduct it at the same time in the morning, immediately after waking up.
What does a low basal temperature indicate?
Low basal temperature (36.5 - 36.8 degrees
), which occurs in the first half of the menstrual cycle, is normal. However, the absence of a rise in body temperature by more than 0.4 - 0.5 degrees in the second half of the cycle may indicate a number of hormonal or gynecological disorders.
The rise in body temperature in the second half of the menstrual cycle is due to the function of the corpus luteum - a temporary organ that is formed from the membrane of a ruptured follicle under the action of luteinizing hormone and which synthesizes progesterones. It is under the action of progesterones on a number of brain structures that a characteristic increase in body temperature occurs. Thus, with an insufficient number of them during the luteal phase of the menstrual cycle, the body temperature will continue to remain at the same, low level.The absence of a rise in body temperature in the second half of the menstrual cycle may be associated with the following pathologies:
- Lack of ovulation. The absence of ovulation is a pathological situation in which the development of the corpus luteum does not occur, and, accordingly, there is no characteristic increase in the level of progesterones with an increase in basal body temperature.
- Lack of luteinizing hormone. Luteinizing hormone is produced by the pituitary gland, a special gland in the brain that is responsible for the coordinated work of most of the body's endocrine glands. The lack of this hormone leads to the fact that the rupture of the follicle is either delayed or does not occur at all. In addition, without luteinizing hormone, the follicle membrane does not turn into a corpus luteum.
- Lack of a number of nutrients. Low levels of a number of vitamins, minerals, as well as cholesterol can lead to the fact that hormones are synthesized either in insufficient quantities, or they will be structurally different from normal sex hormones.
- Structural change in the internal genital organs against the background of infection or other pathology. Changes in the structure of the internal female genital organs, which may occur either against the background of certain infections ( both sexually transmitted and any other ), or against the background of a number of other processes can lead to a change in ovarian function with menstrual irregularities.
- Incorrect change in rectal body temperature. Correct measurement of rectal body temperature should be done in the morning, before getting out of bed and before starting any activity. It is necessary to measure the temperature with the same thermometer in order to exclude the influence of different readings on the results obtained. The most suitable for conducting research is a mercury thermometer, however, due to the rather high danger of its use ( especially when placed in the rectum or vagina ), you can also use an electronic thermometer, the measurement accuracy of which is slightly lower. The most correct is the measurement of the temperature in the rectum, however, the measurement can be carried out by placing a thermometer in the vagina or in the oral cavity. It should be noted that the measurement method chosen at the very beginning must be adhered to until the end of the cycle, since the temperature in different parts of the body may differ by 0.1 - 0.3 degrees.
It should be noted that a body temperature below 36 degrees can be both a variant of the norm and indicate a number of pathologies (some infections accompanied by a decrease in body temperature, brain damage, systemic diseases
). Therefore, if during the study of the basal temperature, a prolonged period with a temperature below 36 degrees was recorded, which is accompanied by additional unpleasant symptoms (headaches, vomiting, general malaise, sleep disturbances, sweating, etc.
), then you should consult a doctor for correct diagnosis and the provision of the necessary medical care.
What does a high basal temperature indicate?
High basal temperature (above 37.5 degrees
) can be observed in the second half of the menstrual cycle and in some women is absolutely normal. However, if this rise in temperature occurred outside the phases of the menstrual cycle, or if it is accompanied by a number of unpleasant symptoms (headaches, vomiting, diarrhea, general weakness, night sweats, pains of various localization, etc.
), then one should assume an infectious and inflammatory process and seek medical help.
Changes in basal body temperature are associated with fluctuations in the concentration of female sex hormones in the blood. In the first half of the cycle, when estrogens predominate, the body temperature is usually kept at 36.5 - 36.8 degrees. Later, after ovulation, when the ovaries begin to produce progesterone, under its influence, the body temperature rises by 0.4 - 0.5 degrees. These changes are cyclical and occur in all healthy women of reproductive age.
It should be noted that initially the basal temperature may be slightly higher, but it should not exceed 37 degrees in the first half of the cycle and 38 in the second. Such values can be associated both with the individual characteristics of a woman, and with incorrect calibration of the thermometer with which the study is carried out. In addition, it must be understood that the temperature in the rectum is slightly higher than the temperature on the surface of the body. However, if the increased body temperature is accompanied by a number of other unpleasant symptoms, then the most likely cause is an infectious and inflammatory process.
Infectious diseases accompanied by a rise in temperature
|Probable infection||Characteristic||Typical body temperature|
|Sexual infections||Many genital infections are either asymptomatic or with extremely poor clinical manifestations. A rise in body temperature is characteristic only for some of them and in some cases may not occur at all. The most common symptoms are the presence of purulent discharge from the genital tract, redness of the vaginal mucosa, itching in the vagina and urethral mouth, pain when urinating, and an unpleasant odor.||Body temperature can be both normal and moderately elevated ( 37.5 - 38 degrees ).|
|Seasonal viral infections||Viruses usually infect the upper respiratory tract, causing general malaise, joint pain, profuse watery nasal discharge, coughing, and sneezing. In most cases, these infections are acute, with a sharp rise in temperature, a pronounced clinical picture. The most typical incidence is in the cold season.||Body temperature can be subfebrile ( 37.5 ), but quite often it exceeds 38 degrees.|
|Tuberculosis||It is a dangerous and common infection that usually affects people with reduced immune reserves. In most cases, the course is sluggish with an unexpressed clinical picture. Usually accompanied by headaches, general malaise, night sweats, fatigue, debilitating and prolonged cough, lung damage. With extrapulmonary localization of the infectious process, many other symptoms may occur.||Body temperature in most cases is subfebrile ( 37.5 degrees ).|
|Intestinal infections||They arise after eating infected food or against the background of prolonged and improper treatment with antibacterial drugs ( which suppress the normal intestinal microflora, thereby opening the way for pathogenic microorganisms ). Are accompanied by vomiting or diarrhea, which can vary in characteristics and duration. In some cases, dehydration associated with diarrhea can pose a significant threat to human life.||Body temperature is usually above 38 degrees. It should be noted that due to diarrhea and impaired intestinal motility during rectal measurement of basal temperature, rather significant errors can occur.|
|Other infections||Many other infections can cause a rise in body temperature, while provoking various clinical symptoms, which depend, first of all, on the localization of the infectious and inflammatory focus.||The temperature can range from 38 to 40 degrees.|
In addition to certain infectious diseases, a rise in temperature may be associated with any nonspecific inflammatory processes (tonsillitis, meningitis, appendicitis, purulent-necrotic processes in soft tissues and other diseases
). All these ailments are usually accompanied by a rather pronounced clinical picture with a rise in body temperature above 38 degrees. Regardless of the cause, a fever with a temperature above 38 degrees is a serious reason for seeking medical help as planned (to the family doctor
), if there are no other disturbing symptoms, or urgently (call an ambulance
) if there are other acute symptoms (pain in the right side, headache with photophobia and inability to bend the head, discharge of pus, skin damage and other symptoms
Basal temperature after ovulation can be a very informative indicator if you have a regular cycle and measure correctly. At first glance, this seems like a useless exercise - measuring basal temperature, but in fact, this indicator will allow you to plan your life. To know how to do this, you need to understand the concept of the relationship between basal temperature and cycle.
What is basal temperature and how to measure it?
Your basal body temperature is your temperature when you are completely calm and resting. Your basal body temperature changes depending on a number of factors, including your hormones. When ovulation occurs, the hormone progesterone causes the temperature to rise. It stays higher during the two-week wait. Then, just before your menstrual period begins, the hormone progesterone drops. And if you are not pregnant, your temperature will drop, because in this case, your temperatures will remain higher because progesterone will remain high.
See also: What is the basal temperature before menstruation?
Thus, hormone levels determine temperature fluctuations. It is this fluctuation that depends on the different hormonal phases that suggest changes associated with ovulation. Actual temperatures are less important than naming a picture showing two temperature levels. Before ovulation occurs, the initial body temperature ranges from 36.1 to 36.3 degrees. This is due to the presence of estrogen, which slows the rate of temperature rise.
After the release of the egg, the rate rises to a new, higher level, usually ranging from 36.4 to 36.6 C. During the next day, the temperature usually rises by at least 0.2 degrees, and then continues to rise slightly. This rise in temperature is caused by progesterone released from the follicle after ovulation. In a few days, it will become apparent that it is in a new, higher range. The rates themselves will continue to rise and fall from day to day, but will remain in a higher range.
Actual temperatures are less important than naming a picture showing two temperature levels. If there is no pregnancy, then your temperature will rise for 10 to 16 days until the corpus luteum regresses. During this time, progesterone levels drop dramatically and you get your period. Your temperature usually drops during this time as well, although it is not uncommon to have erratic or high temperatures during your period.
How to measure temperature? To build a chart of your basal temperature, which will allow you to judge your cycle, you must track your temperature and cycle for at least a month. It is better to start from the first day and follow daily measurements, writing them down. On the first day of the next period, start a new schedule and recording process over and over. Keep charting for at least 3 cycles because this is the only way to know exactly when to expect ovulation.
Take your first temperature in the morning before getting out of bed or even talking - leave your thermometer by the bedside within easy reach so you don't have to move a lot to reach it. If you are using a glass thermometer, make sure you shake it well before bed.
Try to keep your temperature measurement as close as possible to the same time every day - set an alarm if you need to. Measuring within half an hour on both sides of the average measurement time is the best way to control. After all, your pace and temperature can change depending on time (for example, if you usually measure your temperature at 6 am, it is quite normal to measure it between 5: 30-6: 30, but the closer to 6, the better). Normal variation is up to 0.2 degrees per hour - lower if you measure your temperature early, higher if you are late.
It is best to take measurements after at least 5 hours of sleep.
You can measure your temperature on the mucous membranes, vaginally or rectally - just use the same method for the entire cycle.
You should try to place the thermometer in the same way every day (same location, same depth vaginally and rectally).
Plan your temperature on a graph every day, but refrain from predicting too much until the cycle is complete. After three months of charting, you will have your basal body temperature data, which accurately displays ovulation and all the processes to control your cycle and sex life.
Basal temperature changes during ovulation
The level of rise or fall in temperature cannot predict ovulation - and this is the main caveat. But you can know exactly when it already happened and a few days after it happened, thanks to the diagram. Therefore, you cannot judge whether you had sex on the "right days" until ovulation occurs. You are more likely to get pregnant if you had sex in the two days leading up to ovulation.
What is the basal temperature after the day of ovulation? The rate of this indicator fluctuates, but after ovulation there must be a temperature shift of at least 0.4 degrees over a 48-hour period to indicate ovulation. This shift should be higher than the highest temperatures in the previous six days, allowing one temperature to be thrown out as inaccurate (accident, disease). Perhaps the best way to explain this is through an example.
For example, if after ovulation, the basal temperature is 37-37.4 - this is a sign that ovulation has occurred. But if the basal temperature after the expected ovulation is 36.6-36.9, then you can expect that there was no ovulation or inaccurate measurements.
After you see the temperature shift for at least three days or at the end of your cycle, you can mark the midpoint between the follicular phase and the luteal phase temperature, which corresponds to ovulation.
Therefore, you should see an increase of 0.4 to 0.5 degrees higher than temperatures throughout your cycle. If fertilization has occurred, then progesterone does not decrease and keeps the temperature at a stable level. Basal temperature after ovulation during pregnancy is maintained. This leads to the fact that a period of rise in values appears on your chart, which has not fallen for a long time. This may well correspond to pregnancy.
How long is the basal temperature after ovulation? Around the 14th day, your temperature will rise above average. This increase occurs over a period of 10-16 days. Your temperature usually drops around the 14th day. If this does not happen, then it is likely that fertilization has occurred.
For most women, their luteal phase does not change for more than a day or two from month to month, even if the length of their menstrual cycle changes. For example, a woman's cycle can range between 30 and 35 days, but the luteal phase can be 12 or 13 days. If your basal temperature does not rise after ovulation, you need to think about the fact that you are not ovulating. If you don't ovulate, you cannot get pregnant. If you ovulate irregularly, this may indicate a possible risk of infertility. Lack of ovulation is called anovulation and is a common cause of female infertility. Most women with anovulation can take medications that will induce ovulation and help them become pregnant.
See also: Low basal temperature: in the second phase of the cycle, after ovulation, during pregnancy
Sometimes it happens that after ovulation, the basal temperature has dropped - this is a sign of a violation of the level of hormone regulation. Perhaps if you cannot get pregnant at the same time, then you have a progesterone deficiency.
A high basal temperature after ovulation is a sign of ovulation itself, which can be an important indicator for women when planning pregnancy. But before you focus on the regulation of your cycle by tracking basal temperature, you need to build your own chart when observing for at least three months.
, , , 
- Basal temperature and its measurement
- What basal temperature is considered normal
Women planning pregnancy carefully monitor the onset of ovulation - the most suitable period for conceiving a child. And measuring the basal temperature will help to find out the degree of development of the egg.
To do this, you need to keep a graph of measurements and know what the basal temperature should be during the maturation of the egg.
So, you should find out what temperature is basal. It is measured in the anus, in the morning, with an error of no more than two hours, after waking up, provided the woman is completely calm (for this purpose, the thermometer is prepared in advance and placed near the bed so that it can be taken with a minimum of movements). It is under these conditions that external stimuli do not affect the indications. After all, what should be the basal temperature during the day cannot be calculated due to the presence of external factors and the activity of the body.
Basal body temperature can be influenced by factors such as alcohol consumption, inflammation, sex at night, and nervous disorders. To calculate the most favorable days for conception, or days on which the possibility of getting pregnant is reduced to almost zero, it is enough to distinguish between basal temperature readings at different periods of the menstrual cycle.
To obtain objective data, it is necessary to keep a measurement schedule for at least three months. Only then can you track changes in a woman's body during the phases of the menstrual cycle. In the first phase of the cycle, BT can be in the range of 36.4 - 37.0 degrees. During the period of egg maturation, the basal temperature rises and can reach 37.3 degrees. After ovulation, the indicators decrease again and gradually approach the indicators of the onset of menstruation, that is, the first phase of the cycle. What basal temperature can signal the onset of pregnancy? In the body of a pregnant woman, the basal temperature does not fall after the ovulation period, but on the contrary, it can rise and remains stably high, therefore, in the case of temperature indicators from 36.9 to 37.4, in the presence of a delay in menstruation, there is every reason to believe that pregnancy is occurring.
Violation of the usual indicators of basal temperature may indicate the presence of pathologies, inflammatory processes, hormonal imbalance and other health problems of a woman. Therefore, keeping a graph of BT readings will not only help to calculate the most suitable days for conception and the "safe" period, but will also show possible violations at the very beginning of their manifestation. In case of alarming indications, you should consult a gynecologist or endocrinologist, undergo an examination and, if necessary, carry out treatment.
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If you are planning to become a mom, you need to know when ovulation occurs in your body - the most favorable period for conception. You can determine the phase of the cycle using the basal temperature (BT) graph. Consider how the basal temperature changes before, during and after ovulation, we will clarify how to correctly take measurements.
BT schedule for ovulation
The graph shows how the temperature changes during the menstrual cycle. To get accurate information about the periods of the cycle and ovulation, measurements need to be taken within three to four months.
The graph allows you to find out not only about the release of the egg (ovulation), but also about the onset of pregnancy, helps to identify endocrine pathologies. With the BT schedule, it will be easier for the doctor to determine the cause of the disorders in the reproductive system if pregnancy does not occur.
What should be the basal temperature during and before ovulation?
If the menstrual cycle is regular (28 days), then the schedule can be divided into two parts, which correspond to the follicular and luteal phases. From the moment of the onset of menstruation to its end, the temperature drops, and then stays at around 36.3-36.6 degrees. Ovulation occurs 12-14 days before the start of the next menstruation, that is, approximately in the middle of the cycle.
So, if menstruation began on August 1, then the release of the egg is expected from August 13 to 15.
When ovulation occurs, the temperature rises to 37.0–37.3 degrees. Such a sharp temperature jump signals the release of the egg from the follicle. On other days, the temperature can also rise, but one cannot talk about the onset of ovulation, if the indicators have not remained at a high level for several days. It should also be borne in mind that in some women, the temperature at the exit of the oocyte may, on the contrary, decrease.
Why monitor basal temperature during ovulation? These data are needed by those who are planning to conceive a child, as well as those who use a natural method of contraception. If you want to get pregnant, activate your sex life during the release of the egg and a couple of days before. If, on the contrary, you are not yet ready to replenish your family, then 4-5 days before ovulation and at least 2 days after it, give up unprotected intimacy, use contraception.
Basal temperature after ovulation
The increased temperature (37.0–37.3 degrees) is observed after the release of the oocyte and lasts until the onset of menstruation. If conception occurs, then such indicators will remain throughout the entire period of bearing a child. If you mark 37.0-37.3 degrees for at least 18 days (luteal phase), then we can talk about a probable pregnancy.
The difference in temperature between the follicular and luteal phases is on average 0.4-0.5 degrees.
Possible deviations in the schedule
If the basal temperature graph looks different from the one above, this may indicate a number of pathologies:
- With anovulation (the egg does not leave the follicle), the corpus luteum does not form, which secretes progesterone and provokes an increase in temperature. This is reflected in the graph by the stability of temperature indicators without sharp drops and rises. Several cycles without ovulation throughout the year are noted in many women, but if anovulation occurs two or three cycles in a row, this indicates serious violations in the reproductive system.
- When a new cycle begins, an increased level of estrogen is noted in the body, which contributes to a decrease in basal temperature. If it is increased at this time, then we can talk about estrogen deficiency.
- If at the beginning of a new cycle the temperature is low, and after the release of the egg it rises, but only slightly, this is a symptom of estrogen-progesterone deficiency. You can learn more about it here.
- Measure the temperature in the morning immediately after sleep (its duration is at least 6 hours). Before the measurements, you can not get out of bed, sit down, take food, drink, have sexual intercourse. If you do not follow these rules, the data will be inaccurate.
- Use an electronic or glass thermometer. Do not change the thermometer during the entire measurement period.
- Measure the temperature at approximately the same time.
- Choose the measurement method that suits you best: vaginal, rectal, mouth. Experts consider the rectal method the most accurate.
- Take note of any factors that may affect basal temperature before, during or after ovulation. This can be a short or, on the contrary, a longer sleep, intercourse on the eve of measurements, alcohol consumption, colds, stress, overwork, taking medications.
- Start measuring temperature from the first day of the cycle, do not interrupt the measurement during menstruation.
- Take measurements for 3-4 months (as long as possible). Record the results in a table that can be downloaded on our website (plan-baby.ru). You can also see the BT schedule here.
Tracking BT is an effective way to control your reproductive health and increase your chances of conceiving. If the data you received differ from the norm, consult a specialist: self-diagnosis and self-medication can lead to negative consequences.
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A basal temperature schedule is recommended for every woman at least from time to time. It allows you to indirectly judge the state of the reproductive and endocrine systems, its testimony can warn a woman about a probable pregnancy, about hormonal disorders, about the development of some gynecological diseases. So, keeping the basal temperature at high marks during menstruation is considered a sign of endometritis.
However, most often, basal temperature is measured to determine ovulation when planning a pregnancy. Keeping this schedule allows you to calculate the most favorable period for conception or diagnose anovulation when the egg does not mature. Every healthy woman can normally have several anovulatory cycles per year, but if ovulation does not occur from month to month, then we are talking about a serious violation.
As you know, the duration of the menstrual cycle is different for every woman, and the basal temperature schedule is also very individual. But no matter what, ovulation almost always occurs 14 days before the expected date of the next period. For example, if your next menstruation should begin on the 15th, then wait for ovulation on the 1st.
This date divides the entire menstrual cycle into 3 phases (excluding menstruation): the first - before ovulation (follicular), the second - actually ovulation (ovulatory) and the third - after ovulation (luteal or corpus luteum phase).
What is the basal temperature before ovulation
In different periods of the menstrual cycle, the hormonal background of a woman is not the same. In the first phase, the hormone estrogen dominates, under the influence of which the basal temperature is kept at a low level. This is necessary to create optimal conditions in which the next egg in turn will mature and prepare for potential fertilization.
The average basal temperature in the first phase is 36.3-36.5 ° C. It can fluctuate up and down by one tenth of a degree throughout the entire first period of the follicular phase. Before ovulation, there is an increase in BT (and in some cases a slight decrease), and on the day of ovulation it reaches an average of 37.1-37.3 C. These data may differ in each individual case. The main thing is only the condition of the gap in the indicators between the phases.
A lowered (more precisely, normal, physiological) basal temperature is set at the beginning of each menstrual cycle and remains at these levels until ovulation occurs.
What is the basal temperature during ovulation
The day on which the persistent basal temperature makes a sharp jump up (not less than 0.2 C) is the day of ovulation. At this time, the egg cell, ripe for fertilization, leaves the follicle and rushes into the abdominal cavity in anticipation of a meeting with the sperm. She will live only a day, so for conception it would be good if the sperm is already waiting for her here at this time. If you measure basal temperature in order to protect against unwanted pregnancy, then unprotected sex should be stopped 4-5 days before the expected onset of ovulation and contraception should be used at least two days after that.
During ovulation, the basal temperature rises to an average of 37 ° C. At the same time, in many women, on the day of ovulation, a decrease in BT occurs, after which its increase is noted.
What is the basal temperature after ovulation
The basal temperature that has increased on the day of ovulation or immediately after its onset will remain the same until the onset of menstruation. If they did not start, and BT continues to stay at 37-37.2оС even after a delay, then with a high degree of probability the woman has a pregnancy. It is possible to assume that conception took place in this cycle if the basal temperature, which is elevated in the second half of the menstrual cycle, does not drop for at least 18 days.
Between the first luteal and the last follicular phases, there should be a "difference" in temperature of at least 0.4-0.5 ° C. Only in this case can we say that ovulation has taken place in this cycle.
The third period of the menstrual cycle - the corpus luteum phase - proceeds against the background of an increased level of the hormone progesterone, which contributes to a rise in basal temperature. This is necessary to create favorable conditions in which the fertilized egg can maintain its viability, move to the uterus, and divide and develop along the way. An elevated basal temperature will persist during the first four months of pregnancy, while the corpus luteum is functioning. Then its functions are taken over by the placenta formed by this time, and the corpus luteum "unnecessarily" dies off.
Correct basal temperature measurements
It should be noted that in order to obtain the most reliable data, it is necessary to adhere to clear rules for measuring basal temperature. Measurements are taken every morning on an empty stomach at the same time seven days a week. The thermometer should always be near the bed, because it is impossible to get up and make any sudden movements before measuring BT - absolute rest is necessary.
In order for the graph to reflect reality as accurately as possible, BT should be measured after uninterrupted sleep for at least several hours (ideally at least 6). Any violation of these rules and many other factors can affect the performance. Be sure to mark in the graph everything that could distort the measurement results: more or less sleep duration, going to the toilet at night, intercourse shortly before basal temperature measurement, taking medications, colds and other ailments, physical and nervous exhaustion, drinking alcohol, etc. other. When planning a pregnancy, you can take into account the basal temperature schedule, built on the results of at least 3-4 recent months.
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Basal temperature (BT) is the lowest body temperature per day that is reached during sleep. It is measured rectally, at rest, immediately after awakening.
Keeping a chart and measuring basal temperature after ovulation helps in planning and diagnosing pregnancy.
What is basal temperature
Measurement of BT helps to determine the state of the hormonal background, as well as the fertile phase of the cycle.
Many factors affect its performance:
- poor sleep (lack of sleep, frequent awakenings, etc.);
- psycho-emotional stress, stress;
- diseases of the gastrointestinal tract (for example, diarrhea);
- alcohol intake;
- physical exercise;
- sexual intercourse;
- taking certain medications;
- climate change.
These factors must be taken into account when scheduling
BT is essential for assessing the menstrual cycle. Knowing the norms and comparing them with their indicators, it is possible to determine violations and even the presence of diseases of the reproductive system.
- In the first (follicular) phase of the cycle, the BT level ranges from 36.1 to 36.7 degrees;
- The day before ovulation, there is a drop in temperature by 0.5 degrees;
- During and after ovulation, the indicator reaches 37-37.4 degrees;
- Basal temperature after the day of ovulation and the rest of the time before menstruation is kept at around 37 degrees;
- It decreases to 36.7-36.8 a couple of days before the onset of menstruation.
I tell you more about the phases of the cycle in the article Basal temperature in early pregnancy >>>
Deviations from the above figures are also possible. This indicates that the cycle is normal. The main thing is that there is no difference between the phases over 0.4 degrees.
Know ! Even in healthy women, the temperature can be at the same mark for the entire cycle. This indicates anovulatory cycle, that is, a cycle without ovulation and the developmental phase of the corpus luteum.
Menstruation in this case comes on time. This is a rare occurrence that is more typical of puberty or menopause.
Basal temperature charts
To build a reliable graph, you need to know how to measure basal temperature:
- It is necessary to measure the temperature immediately after sleep, you cannot get up. Usually measured after a night's sleep, it should be at least 4-5 hours;
- Measured rectally. There are also vaginal and oral methods, but these are not standard;
- Use the same thermometer to measure. Prepare it in the evening (knock it down and put it closer). Extra movements before measurement are not needed;
- Hold the top of the thermometer so as not to knock down the readings.
The graph must be kept daily, marking the result with a dot, and then connecting all the dots with a line. Usually, a schedule is drawn up not for one cycle, but for several. The graph of one cycle is not very informative.
The graphic image will help to track the change in hormonal levels during the cycle. For plotting, you can use a ready-made graph, of which there are many on the network. Or you can draw it yourself.
The horizontal X-axis indicates the days of the cycle, and the vertical Y-axis indicates the temperature. The result is marked on the graph with a dot, and then the points are connected to each other.
How to determine ovulation
In the first part of the cycle, estrogen is the dominant hormone.
- It stimulates the restoration of the functional layer of the endometrium, its thickening, increases the secretion of mucus in the cervix;
- The increased content of estrogen in the blood induces contraction of smooth muscles, microvilli of the fallopian tubes, facilitating the movement of sperm to merge with the egg;
- The normal indicator for this phase is 36.1-36.7 degrees.
During the ovulatory period, luteinizing hormone is released.
- This hormone is responsible for the appearance of the egg (for ovulation);
- When this hormone is released into the bloodstream, estrogen and BT decrease (by 0.5 degrees). This lasts 24 to 48 hours;
- A longer drop in temperature may indicate problems in the work of the ovaries;
- This is the best time for conception.
How else can you determine ovulation:
- for pain in the ovary;
- for changes in cervical fluid.
After ovulation, the basal temperature rises to 37 degrees. Its increase is influenced by progesterone. It is he who prevails in the second part of the cycle, preparing the uterus for zygote implantation.
Basal temperature after ovulation
Women who want to get pregnant are concerned about the question: what basal temperature after ovulation indicates conception (see also the article Favorable days for conceiving a child >>>).
If fertilization has occurred, the basal temperature after ovulation is kept at around 37-37.4 degrees. In some cases, the indicator allows you to determine the conception before the delay.
There is such a thing as "implantation retraction". This is a decrease in BT for 5-12 days after fertilization. After that, the indicator returns to normal and does not fall anymore.
Important! If conception has occurred and the temperature has dropped, there is a high risk of termination of pregnancy.
Sometimes the temperature drops after ovulation. It might say:
- About the lack of a corpus luteum;
The problem in this case is low progesterone levels. It is this hormone that is responsible for raising the temperature, preparing the endometrium of the uterus for implantation of the ovum.
Also, progesterone prevents the onset of menstruation.
If the sperm does not fuse, the egg dies. Its viability is only 12-24 hours (rarely up to 48).
Due to the absence of a zygote (a fertilized egg), the hormone level drops, and the BT index decreases.
Important! If BT after ovulation remains at the same level, this may indicate hormonal problems. Progesterone deficiency can be a symptom of malfunctioning ovaries.
There are many factors that cause progesterone deficiency and luteal phase dysfunction. They can be associated with pathologies of the organs of the reproductive system, disorders of its functions, etc. Only a doctor can determine this, based on additional diagnostics and test results.
Symptoms Indicating Low Progesterone:
- problems with conception;
- short menstrual cycle;
- early termination of pregnancy.
How to determine conception by basal temperature chart
In order to determine pregnancy using a schedule, it is necessary to conduct it continuously for several cycles.
If the basal temperature rises after ovulation, there is no usual decrease in the rate, pregnancy can be assumed. Usually the indicator is kept at around 37-37.4 degrees.
Important! Temperatures over 37 degrees in the first phase and 37.5 in the second phase may indicate an inflammatory process in the body. For diagnosis and treatment, you must consult a doctor.
BT can be measured to determine conception, but this is not the most reliable way, since many third-party factors can affect it.
This method will be more helpful in determining ovulation and favorable days for conception.
For information on how to prepare for pregnancy and conceive a healthy baby, see the Internet course I want a baby: how to get pregnant, taking into account the wisdom of the female body >>>
Read also :
Basal temperature is a very informative indicator for women. It can indicate ovulation, conception, and even a threat of miscarriage. But you need to measure the temperature correctly! How to measure basal temperature to determine pregnancy?
What is "basal"?
Basal temperature is the one that is determined on the internal mucous surfaces, in particular, in the rectum. It changes due to fluctuations in the strength of the blood supply and inflammatory processes of the pelvic organs.
This temperature is most often measured to determine the date of ovulation, as well as to assess whether conception has occurred and whether there is a threat to bearing a baby.
It is important to know that it is possible to determine ovulation with a thermometer quite accurately. But you should only use this if you want to get pregnant. The calendar method, even with temperature measurements over several months, is rather unreliable.
Studies show that sperm can live in vaginal folds for up to 7 days. And the release of the egg can change due to a variety of factors. So when attempting contraception with the help of schedules, one must be prepared for a sufficiently high probability of pregnancy.
Basal temperature can change not only due to reproductive processes. It also rises when the overall temperature changes - against the background of ARVI, ARI. It is also affected by diseases of the genitourinary system, stress and even alcohol intake!
How and where to measure basal temperature?
Few know, but basal temperature can be measured not only in the rectum, but also in the mouth and inside the vagina.
Since a conventional mercury thermometer is best suited for measurement, it is best not to measure the temperature in the mouth. Most prefer rectal measurements, and experts support this.
The most important thing is when and how to do it. The temperature of the mucous membrane easily changes, so reliable indicators can be obtained only with complete relaxation of the body for at least three hours without interruption.
How to assess basal temperature to determine pregnancy
A change in the temperature of the mucous membrane is one of the reliable signs of pregnancy. Why is that?
- In the second phase of the menstrual cycle (luteal), the corpus luteum is formed in the ovary. If pregnancy occurs, it will release the necessary hormones.
- At this time, the temperature in the vagina and rectum rises to 37.0-37.2 ° C.
- If conception did not occur, by the beginning of the next phase of the cycle, before menstruation, the temperature again drops to normal values.
But if it keeps before the onset of the next menstruation and during the delay of menstruation above 37.0-37.2 ° C, then in healthy women this indicates pregnancy.Take the test Test: you and your health Take the test and find out how valuable your health is to you.
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