During the menstrual cycle the female body produces hormones, which concentration varies depending on the phase of the cycle influencing the main functions of female reproductive organs and thus her fertility. Daily observation of physiological changes that occur periodically in your body will give you the necessary information to determine your fertile days and periods of natural infertility precisely. Conducting self-observation and recording the observed changes will allow you to understand better how your body works, it will also help you to accept these changes and to identify any abnormalities or cycle disorders.
In the following section you will learn how to carry out the observations of fertility indicators during the menstrual cycle, in particular, how to interpret their changes correctly:
- The basal body temperature measurement should be carried out every day at the same time, with the same thermometer and in the same way. Usually it is done in the morning after waking up, but it is also possible to get the proper temperature chart if you are a shift worker. However, there must be at least one hour rest before the temperature measurement.
- The observation of mucus produced by the cervix should be carried out throughout the whole day, during the every visit in the toilet. On the cycle card we register the most fertile type of observed mucus and a feeling which accompanies it.
- The self-examination of the cervix is the additional and complementary observation. It is conducted once during the day and once in the evening. Initially it raises some concerns but it can be very useful for premenopausal women or the women who have difficulties in noticing any signs of mucus on the external genitalia.
- During the preovulatory phase the dominant estrogens cause a slight opening and softening of the cervix and they stimulate it to produce mucus, which function is to transport sperm into the uterine cavity and then to the fallopian tubes. The estrogens don’t influence the basal body temperature measurement so it remains at a low, unchanged level.
- During the postovulatory phase the dominant hormone is progesterone, which causes the closing and hardening of the cervix and also disappearance of its mucus, which is a barrier to sperm. Increasing the concentration of progesterone after ovulation causes the increase in basal body temperature by at least 0.2 ˚ C, and the level of higher temperatures lasts for about 14 days until the next menstrual period. Progesterone also prevents another ovulation in the cycle.
The basal body temperature measurement
The years of research on the physiology of the female menstrual cycle led to the conclusion that changes in concentrations of various hormones produced during each cycle are connected with changes in basal body temperature. In the first - estrogen phase, the body temperature remains unchanged at a lower level, in the next – progesterone phase, it increases by at least 0.2 ˚ C. Observing the basal body temperature (BBT) provides relevant information what your current menstrual cycle phase is.
The temperature should be measured directly after waking up and before performing any activities. It would be good if your rest lasted for at least 6 hours (this is not required, but too short sleep may be the cause of irregularities or disturbances in the cycle). Also keep in mind that about 7:30 the body temperature naturally rises, so measurements conducted after this time will probably be increased. You can get the proper temperature chart if you are a shift worker. If you sleep after night work during the day, measure the temperature immediately after waking up and check on the time of the measurement cycle. You can also try to measure the temperature at any fixed time but just before the measurement you should lie down and rest for at least an hour; the time of the measurement should be registered. The differences in the measurement time should not be more than one hour and a half. The measurement should be carried out inside your body, in your mouth (orally), vagina (vaginally) or rectum (rectally). Measurements conducted under your arm, in the ear or on the forehead are unreliable. Remember that if you measure the temperature in your mouth, it should be exactly the same place every day.
For temperature measurement you can use any type of thermometer. However, you must remember about the specifics of particular types of thermometers:
- electronic thermometers measuring time is very short, but they allow measurement uncertainty of 0.1 °C ;
- using the ovulation thermometer you can read the temperature correctly after 3 minutes of measuring;
- using the ovulation mercury thermometers you can read the proper temperature after 4 minutes (orally) or after 2 minutes ( vaginally and rectally);
- using the regular medical mercury thermometer the temperature should be measured for 8 minutes (orally) or for 5 minutes ( vaginally and rectally).
Do not give up measuring the temperature during the illness. In the case of the sudden increase caused by a disease, the other symptoms you have observed should allow for the correct interpretation of your cycle phases.
Temperature chart interpretation
Menstruation is preceded by a period of at least three higher temperatures, although for the majority of women the higher temperature (or corpus luteum) phase lasts about 14 days. Usually with the menstruation the temperature drops and it remains at low level (the baseline is determined by the highest temperature of the six ones preceding the increase in basal body temperature) until ovulation. Rising temperature means that ovulation has already occurred - the Graafian follicle has ruptured and corpus luteum began to produce progesterone.
The level of the higher temperatures is determined as 0.2 ˚ C above the baseline. A rise in temperature to a higher temperatures level should last for at least three days after the day of mucus peak and it is assumed that immediately after these days the absolute infertility phase begins.
There are sometimes cycles in which the temperature begins to rise, although there are still signs of the observed mucus with fertile characteristics. This is a case of an early rise in temperature. These temperatures should be marked with the ↑ symbol on the cycle card. They are caused by the female body’s sensitivity to progesterone secreted by the granulosa cells of Graafian follicle. Such situations confirm that it is essential to take into account the day of the mucus peak in the interpretation – only after that day you can determine the higher temperatures - in the method described by prof. J. Rötzer we circle them, as certain observations. If the third of the higher temperature doesn’t reach the level of 0.2 ˚ C above the baseline, you should wait with indicating the infertility phase for the fourth higher temperature (it is enough that it remains above the baseline).
If, however, after the mucus peak, one of the three higher temperatures falls to the baseline or below it, this measurement should be skipped and you should wait for the next higher temperature. The occurrence of one day or several days the temperature rise due to illness, stress, travel and time zones change should be marked as interrupted (taken in brackets) and shouldn’t be taken into account when determining the level of the baseline. Single day disturbed temperature can be taken into account while numbering the six lower temperatures before the temperature rise.
The mucus observations
Due to the activity of sex hormones the cells secrete cervical mucus, which is also visible on the external genital organs. Mucus secretions may have a different texture, color and left a variety of sensations in the vaginal vestibule area - its characteristics depend on the dominant hormone during the menstrual cycle. External observation of mucus secreted by the cervix is very simple: you have to look at the secretion left on the toilet paper during each of your visits in the toilet. Rate mucus characteristics: its color and texture and the feeling in the vestibule of the vagina area. If during the whole day you have observed the several features of mucus, select the one with the most fertile character, which provides the most favorable conditions for survival and movement of sperm.
Cervical mucus secretions of less fertile type has the following characteristics:
• non-transparent, opaque, whitish, milky, yellowish;
• sticky, sticky, lumpy;
• leaves a sensation: dry, wet.
Mucus secretions of more fertile type is characterized by the following features:
• transparent, glassy, crystal;
• similar to egg white;
• stretchy (from 2 to up to 15 cm), extending, smooth;
• leaves a feeling of: moist, wet, wet - slippery.
The sensations in the vaginal vestibule often provide more important information than the observed mucus: e.g. the “W” feeling (the “careful observation”, which is the first sign of fertility according to the Rötzer’s method) and the “wet-slippery” feeling when mucus is so smooth that it is difficult to observe, but it leaves an intense feeling of lubrication. Your observations on the cervical mucus should be recorded on the cycle card, using the appropriate symbols.
Interpretation of cervical mucus characteristics
The appearance of any mucus is always a symptom of the beginning of the fertile period, whereas the dry days are considered as the days of natural infertility. Due to the increasing level of estrogen the type of mucus changes from less fertile to more fertile one, until it gets the most optimal characteristics, namely: being stretchy, transparent, wet and slippery. The last day of occurrence any of the most fertile features we define as the mucus peak day and we mark it with ●. This day is the basis for determining the beginning of the natural infertility phase – the third evening of higher temperatures after the peak day determines the end of the fertile days.
Please note that the course of the cycle is dynamic, and therefore can be disturbed by various factors such as: stress, illness, medications, excessive alcohol, lack of sleep or changes of climate zones. Disorders may be seen while observing the mucus. In particular, disturbances can appear in the first phase of the cycle when primary ovarian follicle grows and matures. They can cause that, despite the hormonal changes and the presence of fertile-type mucus, the ovulation does not occur, and after several days the follicular maturation process starts again, the fertile mucus and ovulation occurs, following by temperature rise. This phenomenon is called delayed ovulation.
Some women, during the fertile type of mucus observation, have light, few days bleeding, but it shouldn’t be considered as menstrual bleeding. This is called mid cycle bleeding, defined as bleeding that is not preceded by the higher temperatures phase and it appears in the lower temperatures phase. It is important to note that the period of mid cycle bleeding is the time of possible fertility, this bleeding may cover the cervical mucus. The mid cycle bleeding often occurs in the periovulatory phase. If any kind of mucus does not appear after the bleeding then its last day we consider as a peak day and mark with ●.
Self-examination of the cervix
Some women have difficulties in observing cervical mucus secretion on the external genitalia. In such cases, self-examination of the cervix is recommended, which is an additional and complementary element of fertility signs observations (particularly in the Rötzer’s method). You can control the changes taking place in the cervix in the various phases of the cycle by examining it by touch. This examination raises a lot of concerns, and sometimes the initial difficulties, but it provides some valuable information on the natural periods of fertility and infertility.
The observations are best carried out in the evening, making sure your hands are thoroughly washed and your nails are shortened. The best time to start self-examination is the postovulatory phase because the cervix is lowered and easily accessible then. The uterus is similar to an inverted pear, and its outer estuary resembles the pear narrower part with the hollow in the middle. The hardness of the cervix during the infertile phase is often compared to the nose, while during the fertile phase to the ear lobes. While observing the cervix you can also examine the cervical mucus accumulating at its mouth. The changes in the cervix during the period of fertility allow sperm penetration into the uterus, while in the period of infertility, the infertile type of mucus-type form an effective barrier to sperm. You should be aware that self-examination of cervical mucus interferes with external observations, so you should choose either to observe the outward signs of mucus or cervical examination with an assessment of mucus taken from its mouth.
Interpretation of changes in the cervix
At the beginning of menstruation the cervix, under the pressure of flowing menstrual blood, excretes a thick plug of mucus. During the natural periods of infertility (in the figure below marked in green), the cervix is hard, closed and lowered to the bottom. Thick and sticky mucus (type G) which accumulates again, provides an additional barrier against the intrusion of sperm into the uterine cavity.
As the estrogen level increasing some changes occur in the cervix: it opens up, becomes softer, is lifted and becomes difficult to get during the examination. Under the influence of the smooth mucus (type P) the thick and sticky mucus (type G) becomes thinner and more fertile mucus (type L) appears – it is the beginning of fertile days (in the figure – the fields with a purple frame).
With the approach of ovulation one can observe the presence of mucus accommodating to sperm and creating channels for its transport (type S). There is abundant, slippery mucus secretion (type P), which facilitates the transport of sperm into the uterus and fallopian tubes, it is often so smooth that it is insignificant, and only gives a feeling of intense moisture and lubrication.
After ovulation, the cervix closes quickly, hardens and becomes lowered again; thick mucus accumulates in the mouth of the vagina, causing a sensation of dryness during the examination. Usually after three days after the mucus peak the natural infertility phase begins (marked in green in the figure). Just before the next period there is often the feeling of moisture in the vestibule of the vagina, and sometimes the mucus secretions of the cervix (yellow color in the figure). This is due to declining level of progesterone and estrogen temporarily dominance.
See more: The detailed rules of fertility and infertility determination