What is Natural Family Planning?

Natural Family Planning (NFP) is an umbrella term for certain methods used to achieve and postpone pregnancies. These methods, also called Fertility Appreciation or Fertility Awareness methods, are based on the observation of naturally occurring signs of the fertile phase of a woman’s fertility cycle. Couples using NFP to achieve pregnancy engage in intercourse during the woman’s fertile phase. Couples wishing to postpone pregnancy simply abstain from sexual relations during the time of fertility. No drugs, devices or surgical procedures are used in the practice of NFP.

NFP reflects the dignity of the human person within the context of marriage and family life, promotes openness to life, and recognizes the value of every child. By respecting the love-giving and life-giving natures of marriage, NFP enriches the bond between husband and wife.


Is NFP the Rhythm Method?

NFP is not “Rhythm.”


The Rhythm or calendar method was in use more than 50 years ago. It was based on the assumption that ovulation occurred about the same time in every cycle. This method often proved inaccurate because of the unique nature of each woman’s fertility cycles. Some women have very irregular cycles and almost all women have a cycle of unusual length once in a while.


Modern NFP treats each cycle as unique and is based on over 60 years of scientific research on human fertility. These methods are based on the day-to-day observations of naturally occurring signs and symptoms of the fertile and infertile phases of the current cycle. NFP methods take advantage of the changes associated with ovulation, recognizing that every cycle is unique.


Who can use NFP?

Any married couple can use NFP! A woman need not have “regular cycles.” NFP education helps couples to fully understand their combined fertility, thereby helping them either to achieve or postpone pregnancy. The key to successful use of NFP is cooperation, shared commitment, and communication between husband and wife.


Is NFP morally acceptable?

All major religions including the Catholic Church accept the use of natural family planning to avoid pregnancy when couples have a sufficiently serious reason for spacing babies or limiting family size.


Also, the Catholic Church, some Orthodox churches, some parts of Judaism and an increasing number of Protestants are opposed to sterilization and the use of contraceptive or abortifacient drugs and devices. It should be noted that intrauterine devices (IUD), birth control pills, hormonal implants, patches, morning after pills, and injections can cause abortions as they thin the uterine lining reducing the likelihood that the embryo can implant.


NFP is unique among the methods of family planning because it enables its users to work with the body rather than against it. Fertility is viewed as a blessing, a reality of life that is accepted, instead of a problem to be solved or a disease to be treated.


NFP is also an excellent tool for helping diagnose problems of couples suffering infertility. Treatment of infertility using NFP to monitor the fertility cycle has achieved pregnancy success rates of 70- 80%. This holistic approach honors the integrity of the marriage act, respects the dignity of parents and children, and is consistent with Catholic Church teaching.


What are the signs of fertility?

A woman’s body provides basic signs for identifying the fertile and infertile phases of her cycle. Recognizing the pattern of these physical signs forms the basis for all methods of NFP.


The primary sign of fertility is the mucus released from the woman’s cervix. She learns to observe this normal, healthy, cervical mucus which indicates the days that intercourse is most likely to result in a pregnancy. This external observation may be by sensation, observation, or touch (or in combination).


A second sign is her basal body temperature. Due to hormonal activity, a woman’s resting temperature changes during her cycle. Lower temperatures indicate that ovulation has not yet occurred. Sustained higher temperatures indicate a rise in progesterone which signals that an ovulatory event has taken place.


The third sign of fertility is a change in the position and texture of the cervix.


How does NFP work?

NFP instruction helps a couple identify the most fertile and least fertile days of the woman’s cycle. Understanding that intercourse on fertile days can result in pregnancy, couples using the natural methods must clearly determine their family planning intention; do they wish to achieve or postpone pregnancy?


If a couple wishes to achieve a pregnancy, they have intercourse during the fertile time. If a couple wishes to postpone or avoid a pregnancy, they abstain from intercourse and any genital contact during the fertile time.


What are the benefits of using NFP?

With NFP both spouses are taught to understand the nature of fertility and work with it, whether its to plan a pregnancy, space children, or avoid pregnancy for serious reasons. A couple who uses NFP soon learns that they have a shared responsibility for family planning. The husband is encouraged to “tune into” his wifes cycles and both spouses are encouraged to speak openly and frankly about their sexual desires and their thoughts concerning family size.


How effective are the methods of natural family planning?

When couples are taught by a competent teacher and follow the rules of the method carefully, NFP is highly successful in achieving their intended family plan. Numerous studies, including one by the U.S. government, have shown that the most common NFP methods are 97-99% effective for avoiding pregnancy. That’s as effective as the birth control pill and far more effective than barrier methods. This means that among couples who are well taught in NFP, who have made a clear decision to postpone pregnancy, who understand the rules for avoiding pregnancy and follow them carefully, no more than 3% of these couples will experience pregnancy in a one year period.


Reference: Contraceptive Technology, 17th Revised edition. Robert A. Hatcher, Irvington Press: New York 1998.


As a family planning method, NFP:

– calls for shared husband and wife responsibility

– requires the couple to communicate

– is based on scientific research

– treats each fertility cycle as unique and teaches a couple to observe their signs of fertility on a daily basis

– has no harmful side effects

– is effective for those wanting to achieve or postpone pregnancy

– can be used throughout lifepostpartum, breast-feeding and perimenopause

– is virtually cost free

– builds strong marriages


Other benefits include:

– marriage enrichment and mutual understanding

– effectiveness for spacing or limiting pregnancy

– no harmful side effects

– useful throughout the reproductive life cycle

– appreciation for the blessings of every child

– greater respect for and acceptance of the total person

– morally acceptable

– low cost


What health risks are avoided in choosing NFP?

When undergoing medical or surgical treatment, people will always be faced with potential side effects. Most people are willing to take the risks in order to be cured of their illness. Fertility, however, is not a disease. It is a normal and healthy part of human nature. Learning to live with fertility rather than waging war against it appeals to many people.


The following problems are avoided by couples practicing NFP.


Potential health problems associated with:


Infertility, pelvic infection, laceration of cervix and bowel, perforated uterus, severe bleeding, shock, death due to hemorrhage or infection, increased risk of breast cancer (especially if first pregnancy is terminated), depression, suicide.



Least reliable method of family planning (high failure rate for postponing pregnancy), latex allergy.



Prolonged infertility or unpredictable return of fertility, irregular menses, osteoporosis, decreased libido, weight gain, depression, increased risk of infection and HIV/AIDS.



Urinary tract infections, toxic shock syndrome, allergy to latex, vaginal irritation.



Severe menstrual cramps, heavy periods, pelvic infections, ectopic pregnancy, ovarian cysts, perforated uterus, irregular bleeding, plus all the problems associated with hormonal birth control.

Nuva Ring*:

Irregular bleeding, heart attack, stroke, sinus infection.


Morning After Pill*:

Nausea, vomiting, headache, breast soreness, fatigue, abdominal pain and dizziness.



Acne; leaking or painful breasts; depression; prolonged, heavy and irregular menses or absence of periods; ovarian cysts; infections where rods are inserted; weight gain.


Hormonal Birth Control* (the Pill, Patch, Shot, etc.):

Headaches, depression, weight gain, breast tenderness, reduced libido, gall bladder disease, increased blood pressure, increased blood sugar, risk of strokes and blood clots,
heart attacks, infertility, liver tumors, cancer of the breast and reproductive organs, memory loss, death.



Bleeding, cramping, nausea, vomiting, may cause an incomplete abortion which requires surgery.



Increases incidence of congenital disorders in children conceived during use, vaginal irritations and infections, allergic reactions in men and women.


Female Sterilization:

Increased risk of ectopic pregnancy, painful menses, very heavy periods, regrets (40%), surgical risk of infection and injury to other organs, future hysterectomy.


Male sterilization:

Increased risk of prostate cancer and autoimmune diseases, regret, dementia, pain.

*May also cause an early abortion.


Where can I learn how to use NFP?

The best way to learn NFP is from a qualified instructor; one who is certified by an NFP teacher training program. For more information about NFP instruction available in your community, check our NFP directory.

One More Soul US provides a PDF version of this publication