Natural family planning – The symptothermal method

   How the symptothermal method works

   A woman can only fall pregnant on the day of ovulation, if the ovum is fertilized within approximately 12 hours or 24 at the most.
   The sperm can survive up to five days inside the womb, therefore unprotected sex before ovulation could lead to the fertilization of the ovum.

   What do we need

   All we need is a track sheet and a thermometer, to check the temperature. In order to start, it is very important to know the method, sometimes it might just be enough to look at one or two books or brochures that explain the rules in great detail using examples and exercises. But it would be ideal to have a trained professional at hand, who could introduce you to the method through a course and could answer any questions you might have later.

   How much time do I have to spend on this?

    Apart from the learning period, between 1 and 3 cycles, the time you actually have to spend on the observations is rather little: You will only have to note down the basal temperature (temperature taken after rest, before getting up in the morning) and the results of your cervical mucus examination, a couple of times a day,on your track sheet. With time and experience, you will be able to reduce these examinations to the days before and after ovulation. 

   Cervical mucus

   The mucus, has to be examined a couple of times a day, on physical characteristics, such as appearance and consistency. In order to check appearance and consistency you will have to take a sample from the entrance of the vagina. At night you will note down the results on the track sheet.

   It is said, that during the fertile period the diluted cervical mucus (vaginal discharge) is of the best quality (best conditions for conception). Discharge differs from woman to woman, there are women, who produce large amounts of mucus throughout their menstrual cycle. Others on the other hand, produce hardly any, and it is only during ovulation that it is visible.

   In the beginning of the cycle there will be a certain feeling of dryness, due to a lack of mucus, after menstruation. Then it will get wetter, and the mucus tends to appear white or yellow, and has a creamy, thick, sticky or slimy consistency. As the point of ovulation approaches, due to oestrogen, the dampness increases further and the mucus becomes "stringy" and elastic, it is clear, translucent or reddish (at this point it will look a lot like egg white).


   The temperature has to be taken before getting up in the morning (basal temperature). And it always has to be taken the same way (oral, rectal or vaginal). It is essential, that you have slept for at least a couple of hours beforehand.

   You will note down the temperature on the track sheet, and you will notice that there is a clear difference in temperature, at various stages of the cylce: If you take one temperature before, and one in between ovulation and menstruation, you will notice the latter being around 0.2 to 0.5°C warmer.

   The cervix

   If you have a problem examining the cervical mucus, you can examine your cervix instead. The cervix noticeably changes during the menstrual cycle: After menstruation it will be closed, hard and positioned low inside the vagina. As ovulation nears it becomes softer,is going to open up and rises inside the vagina. After ovulation it will close up again, get hard and lower its position.

   Note: The sypmtothermal rules, published by the WHO stipulate that the examination of cervix, cervical mucus and temperature consider these as three steps as opposed to two.

   Other symptoms

   There are other symptoms, which can indicate ovulation, for example; sensitivity of the breast or ovarian pain.
The breasts can hurt, increase in size, weight, and become taunter, itchier, swollen or sensitive. Although this could be a symptom, it is not a sufficient enough indicator of ovulation, as there are some women, who are not affect by this at all, in some case they coincide with ovulation and in others they experience the same symptoms beforehand.
Pain in the ovaries is not a sufficient indicator either, although it might be additional. The pain can vary in terms of location and intensity. Furthermore neither ovarian pain nor sensitivity in the breast are clearly linked to ovulation,

   How to determine fertile and infertile days

   In order to be able to distinguish fertile from infertile days it is important to precisely obey a set of rules. It is best to learn these, using books and/or the help of a trained professional. All rules mentioned in this part of the web site, will give you a general idea.