Understanding your fertility:

Men are fertile all the time but women are fertile for only about one third of an average cycle. Did you know that a woman’s own body gives her signs which allow her to identify these potentially fertile days of her menstrual cycle?

Planning a family naturally:

By learning to recognise the signs of her fertility (fertility awareness), the couple can time sexual intercourse to plan a pregnancy by using the potentially fertile time of the menstrual cycle or to avoid a pregnancy by using the infertile time of the menstrual cycle.

What are the signs of fertility observed by the woman?

These signs are called the ‘fertility indicators’ and include:

  • changes in the cervical mucus,
  • changes in basal body temperature,
  • changes in the cervix itself


and a statistical minor indicator called the ‘Calendar Rule’.

Does it take long for the woman to learn to recognise the fertility indicators?

Most women irrespective of their educational background will be confident in their observations of the fertility indicators after charting three cycles using the symptothermal double-check NFP method.

How do you know when exactly the fertile phase and the infertile phase of the cycle begin and end; in other words –  what is natural family planning? 

The woman learns how to keep a daily record of her observations of the fertility indicators on a chart, (see text below) as they change during the cycle. Natural family planning is when the couple apply the rules of the NFP method they are using to the signs of fertility recorded on the chart in order to define when exactly the fertile and infertile phases of the cycle begin and end. These rules are based on numerous scientific studies done in recent decades by the World Health Organization among others. NOTE: The woman must be taught how to apply the NFP rules to the fertility indicators by a qualified NFP teacher.

What are the methods of natural family planning (NFP)? 

There are two main methods of NFP,

  1. The ‘symptothermal double-check method’ taught by our Association (NFPTAI).
  2. The Billings ovulation method.

How do these NFP methods differ? 

They differ in the number of fertility indicators used in each method.

  • The symptothermal double-check method uses changes in two indicators ‘cervical mucus’ and the ‘calendar rule’ to define the beginning of the fertile phase, and the changes in two indicators ‘cervical mucus’ and ‘basal body temperature’ to define the end of the fertile phase.
  • The Billings ovulation method uses the changes in one indicator ‘cervical mucus’ to define both the beginning and end of the fertile phase.

Achieving pregnancy – the effectiveness of NFP:

In planning a pregnancy, couples can use their knowledge of fertility awareness and natural family planning to time sexual intercourse to the potentially fertile time of the cycle in order to increase the odds of conception.

Avoiding pregnancy – the effectiveness of NFP:

The symptothermal double-check method of natural family planning which is taught by our organization (NFPTAI), is very effective, about 98%, in avoiding pregnancies and in this regard it is as effective as the ‘Pill’ and more effective than barrier methods (e.g. condoms). In order to achieve high effectiveness, couples need to be taught the natural family planning rules by a qualified NFP teacher and must adhere to these NFP rules. It is important to note that no method of family planning, whether natural or artificial, is 100%, effective in avoiding pregnancy.

A brief explanation of what the woman does when she uses the symptothermal double-check method of NFP:

In the symptothermal double-check method, the woman takes her temperature each morning and observes a secretion, cervical mucus, which originates in the neck of the womb. The woman records these two signs every day in a special chart, and also records the length of her previous cycles, (the calendar data). These recorded observations enable her and her spouse to determine, day by day during her cycle, whether that day is fertile or not. These observations become routine in a short while, are simple to learn, and women themselves are pleased to know when the fertile time begins and ends.

Is the old rhythm method the same as modern methods of natural family planning? 

The old rhythm method of natural family planning is not the same as the modern methods of NFP. The calendar or rhythm method which was developed in the early 20th century was based on statistics collected from many women. It did not instruct women on how to detect the signs of their own fertility and for this reason was much less effective than modern NFP. Nowadays the calendar or rhythm method of NFP is never used. In the symptothermal double-check method of NFP the calendar rule is used as one indicator that is double-checked with the cervical mucus symptom to define the beginning of the fertile phase of the cycle.

Natural family planning is an eco-friendly method of fertility regulation as no hormones or chemicals are used and there is no interference with the normal physiology of the menstrual cycle, is scientifically based, is effective, and can be used throughout the child-bearing years.