How it works

A prerequisite for pregnancy is that the egg cell and sperm cell (sperm) come together. The egg is released from the ovary only once in the cycle. It is not even capable of fertilization for a whole day. The sperm, on the other hand, can survive in the female body around ovulation for 3 to a maximum of 5 days. During this time, body temperature, cervical mucus and cervix change particularly significantly. A woman observes these bodily signs daily, enters them in a so-called cycle sheet and evaluates them according to easy-to-understand rules. In this way, she is able to determine her fertile phase and to aim for or avoid pregnancy.

Important terms and notes

Body temperature

If you follow the course of your body temperature, the so-called basal body temperature measured in the morning, for one cycle, you will notice that there are two temperature levels. Before ovulation, the temperature is somewhat lower; around ovulation, it rises noticeably by a few tenths of a degree. This effect occurs due to the hormone progesterone, which plays an important role in the second half of the cycle.

This observation makes it possible to determine with certainty the beginning of the infertile period after ovulation.

Glands in the cervix (neck of the uterus) produce cervical mucus of varying quality and quantity throughout the cycle. Generally, a woman will first notice cervical mucus a few days after her menstrual period. Initially, it is thickish-tough, sometimes sticky-creamy and often whitish in colour.
As ovulation approaches, the cervical mucus becomes more abundant and fluid, and at the same time clearer - almost like egg white. Then it has the consistency that allows sperm to penetrate through it to the egg and also survive for a few days in the uterus, waiting for ovulation.

After ovulation, the cervical mucus thickens again, closes the cervix like a plug and becomes impenetrable for sperm again. Every woman can observe this process.

When abundant cervical mucus flows down the vaginal walls during the fertile phase, there is a moist or wet feeling in the vaginal area. When dabbing the vagina, a woman can see what the cervical mucus is like, whether it is thick or thin, and what colour it is, yellowish or whitish.

The individual cervical mucus pattern during the menstrual cycle can vary from woman to woman. The cyclical changes in cervical mucus are caused by the hormone estrogen.

Women can recognize the change in her fertility by yet another bodily sign: the changes in the cervix. It protrudes into the vagina in the shape of a ball or cone.

In the course of the cycle, regular palpation clearly shows how the position and firmness of the cervix and the opening of the cervix change. This self-examination is not necessary in every case to identify fertile and infertile days. However, it can sometimes be an additional help - as during menopause or after the birth of a child.

The changes of the cervix in the cycle are caused by the hormone estrogen. This combination of observing the symptoms of cervical mucus or cervix (sympto) and body temperature (thermal) also gives the method its name: symptothermal method.

Temperature values and cervical mucus changes must be evaluated and interpreted according to very specific rules so that Sensiplan can be used safely. For this purpose, there is a detailed set of rules that is easy to learn and enables the fertile phase to be reliably narrowed down.

The rules can be read in detail in the handbook "Natural and Safe".

The evaluation and thus the safety of the method with Sensiplan is based on double control. This means that two independent observations are used and evaluated to determine the beginning and end of the fertile period within each cycle. Only after both evaluations have been completed can a reliable statement be made about the fertile time.
At the beginning of the cycle, it is - for the beginning of the fertile time - the first appearance of cervical mucus in double control with the 5-day rule, or the minus-8 rule, which is based on the earliest first higher temperature measurement.

For the end of the fertile period, it is the evaluation of the cervical mucus pattern in double control with the evaluation rules of temperature.

In order to avoid errors caused by "incorrect" temperature measurements, it is necessary to enter interfering factors that could cause a "wrong temperature rise" in the cycle sheet under "Special features and interferences".

It is known from many years of experience that not only illness, but also stress, evening meals, celebrations, and also a poor night sleep can cause a slight increase in temperature in some women.

In order for the individual woman to know for sure which changes are to be expected in her and when, she is requested to very systematically note down her cycle and symptom observations in her cycle diary, the so-called cycle sheet, during the first three application cycles.