Is NFP Effective?


Although there is less skepticism with regard to NFP’s effectiveness these days, Natural Family Planning still gets a bad rap from many in secular society. I’ve heard more than a few people say, “NFP didn’t work for us.”

When the rules are followed, NFP can be 99 percent effective in avoiding pregnancy and works well to achieve pregnancy.

A brief overview of how NFP works: a couple charts the woman’s signs of fertility and determines when she is fertile. If the couple is avoiding pregnancy, they abstain from marital relations in the fertile time and only have relations in the infertile times (the average length of abstinence is between one and two weeks, depending on the couple).

Here are some of the most common reasons people think NFP isn’t effective:

1. The couple chooses not to follow the rules or they take “shortcuts.” On numerous occasions, a couple indicated that they were using NFP to avoid pregnancy, then they became pregnant. Upon questioning them, the couple shared that they had relations during the fertile time. “It was only one time.” One time is all is takes for a normal healthy young couple to become pregnant.

2. The couple chooses to use barrier methods in the fertile time. Couples who use contraceptive methods (condoms, diaphragm) during the fertile time may experience an unplanned pregnancy at some point if they continue contraceptive use. NFP’s 99 percent effectiveness rate depends on abstinence in the fertile time. If a couple does not abstain, the effectiveness rate will drop to whatever barrier they’re using. Contraceptive use is contrary to the teaching of the Church and is considered serious sin.

3. “We can’t abstain.” Abstinence is difficult. We don’t try to skirt the issue. But just because something is difficult doesn’t mean it’s impossible. A strong sacramental life is essential to assisting couples having difficulties with abstinence.

4. “My cycles are irregular.” NFP is not the old rhythm method. Most of the calculations and rules are based on a woman’s present cycle. Therefore, women with irregular cycles can use NFP effectively. As well, irregular cycles can sometimes be an indicator that something unusual is going on in the body. Improved nutrition, exercise and simple changes in lifestyle can often produce dramatic results.

No method of birth regulation is 100 percent effective in preventing pregnancy. NFP is around 99 percent when the rules are followed and works well to achieve pregnancy too.

Our own experience illustrates the effectiveness of NFP. My husband, James, and I were very young when we got married, so for the first four years of our marriage, we used NFP to avoid pregnancy. At the end of James’s last year of university, we decided to use NFP to seek a pregnancy. We became pregnant (with twins) in the first cycle. We unfortunately lost those babies early in the pregnancy. But over the next 25 years, we have been successful in avoiding pregnancy when we have had a serious need to do so; and equally successful in becoming pregnant when we have desired it (we have five sons ages 12-24). We were able to use NFP in the postpartum periods and have been able to use it effectively during pre-menopause.

When the rules are followed, NFP is extremely effective in avoiding pregnancy and can work equally well in helping couples to achieve pregnancy. (This is the only method that can work both to avoid and achieve pregnancy.)

We currently offer NFP classes online (classes are limited to eight couples). If you’re interested or have any questions about NFP or its effectiveness, please contact me at or leave a comment below.

Copyright 2012 Ellen Gable Hrkach


About Author

Ellen and her husband, James, have been certified NFP teachers for the Couple to Couple League since 1984 and teach Theology of the Body to teens. She’s also an award-winning, bestselling author of ten books, an editor, a publisher and a self-publishing book coach. Her newest novel is Ella's Promise. The mother of five adult sons and grandmother of one precious grandson, Ellen lives in Pakenham, Ontario with her husband. Contact her at Full Quiver Publishing.


  1. Reading about the effectiveness of NFP leaves me feeling sad and depressed. My cycles are so irregular that NFP can’t identify any infertile days. So to follow the rules means complete abstinence. I have been living with this irregularity for years, and I feel ignored. I am currently charting with the Creighton Method (but have used the Symptho-Thermal and Billings Methods in the past) with the help of a Creighton teacher and physician. I have had two Cervical Hyphercations in the past several months (and my doctor says I may need another), and am now taking two powerful antibiotics in an attempt to clear up constant fertile type mucus. We have serious reasons to avoid pregnancy as we are raising nine children, several with special needs. We are poor and don’t have assistance from family or friends. I feel very alone. My friends are feeling burdened, and a few (NFP-using) have suggested that I use contraception. The relationship between my husband and I is strained because we can’t enjoy the unitive aspect of the marital embrace. We feel caught between complete abstinence and contraception. Although we are a small minority within the NFP-using population, we exist and we should not be ignored.

    • Emma Willcox on

      Have you heard of the Marquette method? It involves using a Clearblue Easy Digital Fertility Monitor which detects periods of fertility and infertility. You insert test sticks into concentrated urine, insert the stick in the monitor, and it tells you how fertile you are. It can be used to avoid pregnancy.

  2. Hello and thanks so much for sharing your personal and painful story. I can assure you it was not my intent to leave anyone feeling sad and depressed. I’m so sorry that NFP has been difficult for you to practice. Your case is unusual and unique. And I agree that you should not be ignored. I can understand why you feel caught between complete abstinence and contraception.

    I would never suggest that you use contraception as the Church teaches it is a grave sin.

    If you have irregular cycles and fertile mucus all the time, there is probably an underlying reason for it. I highly recommend you read a book called “Fertility, Cycles and Nutrition” by Marilynn Shannon

    You mentioned that you used the Sympto-thermal method of NFP in the past. Within this method (which the Couple to Couple teaches), we do have a rule for women with all-the-time mucus. It is a temperature-only rule and may provide some infertile days after ovulation.

    Another thing I would highly recommend is getting spiritual direction from a faithful priest who can assist you spiritually during this difficult time.

    Also, I will be sending you a private email with more detailed questions and information in case you want to discuss this issue further.

    God bless you…

  3. You said, you were able to use NFP postpartum – can you tell me were to look for instructions in this case? I use the symptho-thermal method following an austrian doctor – Joseph Rötzer, he mentions the possibility in the book I have, but…)
    Thank you so much in advance!

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