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NFP Effectiveness


How effective are NFP Methods?

NFP methods can be very effective for both postponing and attempting pregnancy!

This is important news to married couples. Typically, "effectiveness" in family planning means "avoiding" pregnancy. In NFP education however, both husband and wife learn about their combined fertility and are taught how to live in harmony with God's design. They are encouraged to discern whether God is calling them to attempt to conceive a baby or to postpone conception.

God calls married couples to be stewards over His gifts of the power of life and love. God entrusts parenthood to husband and wife as one of His most precious gifts. NFP methods are the only authentic approach to true responsible parenthood because they respect God's design and gifts for married love!

Attempting Pregnancy

When couples wish to attempt pregnancy, they can time sexual intercourse to the fertile window of the menstrual cycle thereby optimizing the possibility of becoming pregnant. Without this knowledge, many couples (up to 85%), will take twelve months to become pregnant. NFP methods give a healthy married couple the advantage of shortening the time to pregnancy. Some NFP methods even dramatically reduce the time to pregnancy (see below).

Avoiding Pregnancy

NFP research shows that married couples who understand and follow their NFP method’s guidelines correctly and consistently, can achieve high rates for postponing pregnancy (e.g, 97-99%).

Married couples who are unclear about their family planning intention (i.e., spacing or limiting pregnancy), or do not understand their NFP method well, or are less motivated and do not consistently follow the method’s guidelines, will have lower rates for postponing pregnancy (e.g., 80-90%).


For articles that review foundational NFP research see: Hanna Klaus, MD, Natural Family Planning: A Review.; see also  Manhart, M. D., M. Duane, A. L. Lind, I. Sinai, and J. Golden-Tevald. "Fertility awareness-based methods of family planning: A review of effectiveness for avoiding pregnancy using SORT."  Osteopathic Family Physician.  5 (2013): 2-8.

To view a list of NFP scientific research demonstrating effectiveness for postponing pregnancy see NFP Bibliography/Effectiveness. See also the research menu at

To read about NFP effectiveness for reducing the time to pregnancy see:

Billings Ovulation Method (BOM)
- 4.7 months for 78% of couples to conceive
See “Study on the Billings ovulation method™ and the achievement of pregnancy.”

Creighton Model FertilityCare (CM)
- 1 month for 76% of couples to conceive
- 3 months for 90% of couples to conceive
See Hilgers T. W., Daly K. D., Prebil A. M., Hilgers S.K. “Cumulative pregnancy rates in patients with apparently normal fertility and fertility-focused intercourse.” Journal of Reproductive Medicine  37 (1992): 864-866.

Sympto-Hormonal Method (SHM)
- 2 months to conceive
See Robinson J. E., Wakelin M., and Ellis J. E. “Increased pregnancy rate with use of the ClearBlue Easy Fertility Monitor.” Fertility and Sterility 87 (2005): 329–334. (Note: the Marquette Model makes use of the ClearBlue Easy Fertility Monitor.)

Symtpo-Thermal Method (STM)
- 6 months for 81% of couples to conceive
See Gnoth C., Godehardt E., Frank-Herrman P., and Freundl G. “Time to pregnancy: results of the German prospective study and impact on the management of infertility.” Human Reproduction 18 (2003):1959-1966.

For additional studies see the NFP Bibliography in this website.


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