Natural Family Planning (NFP)

What is natural family planning?

Natural family planning (NFP) refers to methods used to determine the fertile and infertile days in a woman’s cycle. NFP is not only used for contraception, but also helps couples who wish to have children to plan a pregnancy. Natural family planning is based on the careful observation and recording of natural physical changes that women experience during their cycle.

The physical signs observed include, amongst others, basal body temperature and changes in cervical mucus. The accuracy of NFP increases with the number of physical signs observed. For this reason, the symptothermal method, which involves monitoring two or more physical signs, is considered the most reliable method of natural family planning.

How does natural family planning work?

Natural family planning (NFP) is based on the daily monitoring of certain physical signs to identify the fertile days in the menstrual cycle. The following physical signs are observed:

• Body temperature: Body temperature is measured immediately upon waking (basal body temperature) in the mouth, vagina or rectum. A rise of 0.2 to 0.4 °C after ovulation indicates the start of the infertile phase. This temperature remains at this level during the second half of the cycle.
• Cervical mucus: The consistency of the cervical mucus at the entrance to the vagina changes over the course of the cycle. Shortly before ovulation, it becomes thin and clear, indicating the fertile days, whilst after ovulation it becomes thicker again. These changes can be felt and seen.
• Cervix: The cervix, i.e. the lower end of the uterus, is closed before ovulation and feels firm; during the fertile days after ovulation, it is soft and slightly open. The cervix can be felt with a finger.

What types of natural family planning are there?

Natural family planning (NFP) offers various techniques for identifying the fertile phases of the cycle. Here is an overview of the most common methods:

Calendar method (Knaus-Ogino method)

This method involves calculating a woman’s fertile days in her cycle. To do this, precise records of the cycles must be kept for at least half a year, after which the fertile and infertile days are calculated using a table or a cycle computer, based on the longest and shortest cycles.

A very regular cycle is essential for this, which very few women have. For this reason, the calendar method is not recommended if reliable contraception is required. The Pearl Index is between 15 and 20. This means that out of 100 women who use this method for contraception for one year, 15 to 20 will become pregnant.

Billings Method (observation of cervical mucus)

This method involves determining fertile days by daily observation of the amount, consistency and colour of cervical mucus. During fertile days in particular, the cervical mucus is thin, clear and stringy. There are several factors, such as hormonal fluctuations, illnesses and psychological factors, which can influence the consistency of cervical mucus. For this reason, observing cervical mucus on its own is not considered very reliable; the Pearl Index for this method is around 25.

Basal body temperature measurement

With this method, ovulation is determined by measuring basal body temperature daily over several cycles. After ovulation, a rise in temperature of 0.2 to 0.5 °C is observed. It is important to take your temperature before getting out of bed, ideally at the same time each day and in the same place (mouth, rectum or vagina). After a few months of recording, the following can be calculated for subsequent cycles: from the third day of the temperature rise until the next period, reliable contraceptive protection is provided, and the first six days of the cycle are considered safely infertile.

This method is also not recommended if reliable contraception is desired. Basal body temperature measurement requires a great deal of discipline and a regular daily routine. Furthermore, stress and illness can alter the cycle and thus the calculated infertile days. The method has a Pearl Index of 0.8 to 3.

Symptothermal method

This method combines the Billings method with basal body temperature measurement and determines fertile and infertile days based on physical signs such as waking temperature and the consistency of cervical mucus, as well as, where applicable, observation of the cervix. These observations are recorded and analysed on a cycle chart or in an app. The symptothermal method requires some effort and discipline, as well as a learning phase. Couples must abstain from sex during fertile days or use additional contraception. When used correctly, however, it is considered the most reliable method of natural family planning. The symptothermal method has a Pearl Index of 0.4 to 1.8.

This method also requires a regular daily routine and discipline, and is more suitable for women who do not wish to rule out pregnancy entirely. Certain medical conditions or the use of various medicines can distort the test results. The Pearl Index for this method is 6.

Cycle monitor (contraceptive computer)

This method involves using a mini-computer to analyse test strips with first-morning urine. Several test strips are required each month. The computer analyses the concentration of hormones in the urine and indicates fertile and infertile days.

This method also requires a regular daily routine and discipline, and is more suitable for women who do not wish to rule out pregnancy entirely. Certain medical conditions or the use of various medicines can distort the test results. The Pearl Index for this method is 6.

What are the advantages of natural contraception compared to hormonal methods?

Natural Family Planning (NFP) offers several advantages over hormonal contraceptive methods:

• No side effects: Unlike hormonal contraceptives, which are often associated with side effects such as weight gain, mood swings, headaches and irregular periods, natural contraceptive methods have no side effects.
• Natural cycle: Whilst hormonal contraceptive methods suppress ovulation, this does not happen with NFP. Hormone levels remain in their natural balance.
• Lower costs: Natural contraceptive methods are generally more cost-effective than hormonal alternatives.

What are the key tips for NFP?

Natural Family Planning (NFP) requires understanding and practice. Here are a few tips:

• The right method: Find the NFP method that best suits your lifestyle and goals.
• Understanding your body’s signs: Get to know your body’s natural signals so you can accurately identify your fertile and infertile phases.
• Allow time to prepare: Invest time in learning your chosen method thoroughly before relying on it.
• Consistency and discipline: Be consistent in applying the method and disciplined in your daily monitoring and record-keeping.
• Communicate with your partner: Talk openly with your partner about the chosen method to ensure that both partners are informed.
• Seek professional advice: Consider seeking advice from experts and, if necessary, attend an NFP course.
• Be patient: Be patient with yourself, as it may take a while before you have fully mastered the method and can use it effectively.