Natural Family Planning (NFP) refers to the practice of achieving or avoiding pregnancies according to an informed awareness of a women’s fertility. In our diocese, NFP courses are presented by the Couple to Couple League.


Frequently Asked Questions
about Natural Family Planning


What is Natural Family Planning?

Natural Family Planning (NFP) refers to the practice of avoiding or achieving pregnancy according to an informed awareness of a woman’s fertility. It can also refer to the spacing of pregnancies through Exclusive Breastfeeding.

What is involved in “fertility awareness”?

During each monthly cycle, a woman normally becomes fertile and then infertile. Her body provides certain signs to indicate her fertile and infertile times. Natural Family Planning’s Sympto-Thermal Method teaches you how to observe and interpret these signs enabling you to achieve or avoid pregnancy naturally by becoming aware of your body’s fertility cycle.

What is the Sympto-Thermal Method?

The Sympto-Thermal Method is NOT Calendar Rhythm! It was developed by leading obstetrician/gynecologists and has been taught for over 30 years by the Couple to Couple League. With this method, a woman observes two or three fertility signs which occur naturally within her monthly cycle. As the signs are observed and recorded, her fertile and infertile times are determined.

What are the fertility signs?

The two most commonly used signs of fertility that NFP’s SYMPTO-THERMAL METHOD teaches you to observe are a woman’s normal cervical mucus secretions and her waking temperature. A third and optional sign is the physical change that occurs in her cervix.

Does it take much time each day for fertility awareness?

Not at all. It takes just about a minute each morning for a woman to take her waking temperature with a digital thermometer. Then during the day she takes a moment while using the restroom to observe any signs of her cervical mucus. Once the information is recorded, she has a complete and cross-checking picture of her fertility . . . it’s very simple and non-intrusive.

How effective is Natural Family Planning?

A number of studies have shown that the Sympto-Thermal Method of NFP can be used at the 99% level of effectiveness for avoiding or spacing pregnancies. It is interesting to note that throughout the history of modern “birth control,” the moral means of achieving this end that have been recommended by the Catholic Church were never less effective than the most effective immoral means available at the time. The Ogino-Knaus Rhythm Method, developed in the 1930s, was as effective in birth regulation as the most effective artificial method of the day — prophylactic condoms and diaphragms. By the time the Pill was developed in the late 1950s, the modern methods of NFP were also achieving similar rates of effectiveness in studies, though far less public and media attention was paid to that research.

What is the difference between the Rhythm Method and modern NFP?

Calendar Rhythm basically assumed that women would have 28-day cycles with ovulation around Day 14. It was ineffective if cycles were either shorter or longer. Modern NFP acknowledges that a woman can routinely have cycles that are shorter or longer than the “average” of 28 days, and that her cycle can even vary from month to month. NFP users make their interpretation choices based on the fertility symptoms they are currently experiencing this month, which is why it is still highly effective for women with irregular cycles, unlike Rhythm.

What are the advantages of Natural Family Planning?

  • Medically safe because NFP is 100% natural, there are no health risks from harmful drugs or devices.
  • Increased health awareness because NFP teaches you to become aware of your normal fertility pattern, changes in this pattern can alert you to medical problems.
  • Effective: As mentioned earlier, the Sympto-Thermal Method of NFP is highly effective both for avoiding and achieving pregnancy.
  • Low cost: NFP costs significantly less than other forms of birth control. Once you learn it, there are no continuing costs.
  • More satisfying marriages: Most couples report that NFP has a positive effect on their marriages. They find that periodic abstinence helps keep their sexual relationship fresh, improves their communication, and gives them a deeper respect for each other. This results in a lower divorce rate among FNP users
  • All the major religions including the Catholic Church accept the use of Natural Family Planning for spacing pregnancies in the context of marriage and a “just” reason for family planning.
  • NFP users do not have to worry about the potentially abortifacient effects of many types of hormonal birth control (See the Catechism of the Catholic Church, section 2368. Also, What Does the Bible Say about Birth Control?)
  • Immediately reversible: You just change your timing. There’s no damage to your fertility from drugs and medical procedures.

What effects will my medication have on my use of NFP?

NFP can be used effectively by women even when they are on prescription medications. It is important to realize that some drugs may affect fertility symptoms adversely and be aware of potential disturbances that they may cause in the menstrual cycle. There is an entire chapter that discusses the effects of many common medications on fertility symptoms in the CCL manual, The Art of Natural Family Planning.


Check out the Couple to Couple League website.