Natural Family Planning (NFP) is the general title for the scientific, natural, and moral methods of family planning that can help married couples either achieve or postpone pregnancy.

NFP methods are based on the observation of the naturally occurring signs and symptoms of the fertile and infertile phases of a woman's menstrual cycle. No drugs, devices, or surgical procedures are used to avoid pregnancy.

Since the methods of NFP respect the love-giving (unitive) and life-giving (procreative) nature of the conjugal act, they support God's design for married love!


The questions below provide general (non-method-specific) information about NFP. The USCCB provides this content in a brochure for purchase. Please see below to order. For a more detailed overview of the philosophy, science, and method categories of NFP, read the Introduction to NFP.

Common misconceptions about NFP are discussed in NFP Myth and Reality.

Natural Family Planning

Is NFP based on guesswork?

Not at all!

NFP is based on scientific facts about fertility. The methods are developed from research about women's menstrual cycles and the signs of female fertility.

Over a century ago, scientists discovered cyclic changes in cervical mucus and their relation to ovulation. In the 1920's, scientists identified the temperature rise that signals ovulation. But it wasn't until the 1950's that scientists developed programs to teach others how to observe and interpret these fertility signs. Today, ongoing research continues to refine the methods of Natural Family Planning.

Who can use NFP?

Any married couple can use NFP! 

A woman need not have "regular" cycles. NFP education helps couples to fully understand and interpret their combined fertility, so that they can discern when to postpone or attempt pregnancy. The key to the successful use of NFP is cooperation and communication between husband and wife—a shared commitment.

What are the methods of NFP?

Each NFP method is focused on one or more signs of female fertility. They can be grouped into three categories:

  1. Cervical Mucus Methods (CMM)
    The methods that observe cervical mucus are commonly called the "Ovulation Method" or "OM." In NFP education, a woman learns how to identify the normal, healthy, cervical mucus which indicates the days that sexual intercourse is most likely to result in pregnancy. A number of NFP providers teach a variety of approaches to the observation and charting of cervical mucus (e.g., Billings Ovulation Method Association—USA, Creighton Model FertilityCare™ Centers, Family of the Americas, etc.).
  2. Sympto-Thermal Methods (STM)  
    The methods that observe several signs of fertility and cross-check two or more of the signs to pinpoint ovulation are commonly called the "Sympto-Thermal Method" or "STM." STM typically combines charting of the Basal Body Temperature (BBT) and cervical mucus with other optional indicators, such as changes in the cervix and secondary fertility signs. A number of NFP providers teach a variety of approaches to the observation and charting of these signs (e.g., Couple to Couple League, Northwest Family Services, various diocesan programs, etc.).
  3. Sympto-Hormonal Method (SHM)
    The method that observes several signs of fertility and adds the use of an ovulation predictor kit (OPK) or fertility monitor is called the "Sympto-Hormonal Method" or "SHM." Similar to the STM, this approach adds the self-detection of reproductive hormones in the urine with the assistance of an OPK or fertility monitor. Various diocesan NFP programs make use of the SHM as well as Marquette University's Institute for NFP (Marquette Model).

What are the signs of fertility?

While in her fertile years, a woman’s body provides several basic ways to identify the fertile and infertile times of her menstrual cycle. The rise and fall of reproductive hormones is responsible for these signs. Recognizing the pattern of those physical signs forms the basis for all methods of NFP.

Around the time of ovulation, a fluid or “mucus” is released from the woman’s cervix (the opening of the uterus). When cervical mucus is present, it has the ability to keep sperm alive in the woman’s body for several days.

Another sign of fertility that can be observed is a woman’s daily waking temperature or “basal body temperature” (BBT). The BBT is taken after several hours of uninterrupted sleep. A woman’s BBT is lower prior to ovulation and will rise .4 to .6 degrees Fahrenheit and stay elevated after ovulation. The higher elevated temperature signals the end of the fertile time.

An additional sign is a change in the shape or texture of the cervix itself. During the infertile time of the menstrual cycle, the cervix is low, closed and firm. Around the time of ovulation the cervix is high, open and soft.

With the development of ovulation prediction kits (or OPKs), the rise of certain reproductive hormones such as estrogen and luteinizing hormone (LH) can be observed. Finally, other optional signs, such as breast tenderness or minor abdominal pain at the time of ovulation, can also be observed by the woman.

How does NFP work?

NFP instruction helps married couples learn how to observe, interpret and chart the wife's signs of fertility. This enables husband and wife to identify the fertile and infertile phases of the wife's menstrual cycle.

When husband and wife wish to attempt pregnancy, they will understand that intercourse during the fertile phase of the wife's menstrual cycle will likely result in pregnancy. When wishing to postpone a pregnancy, husband and wife would abstain from sexual intercourse and any genital contact during the fertile time. No artificial methods are used during the fertile time.

NFP is unique among methods of family planning because it enables its users to work with the body rather than against it.Fertility is viewed as a gift and a reality to live, not a problem to be solved. The methods of Natural Family Planning respect God's design for married love!

NFP represents a unique approach to responsible parenthood because it

  • calls for shared responsibility by husband and wife
  • is based on scientific research about the signs of fertility
  • treats each menstrual cycle as unique
  • teaches husband and wife to daily observe the signs of fertility
  • has no harmful side effects
  • maximizes the possibility of achieving pregnancy when intercourse takes place during the fertile phase of the wife's menstrual cycle
  • is effective for postponing pregnancy when intercourse takes place during the infertile phase of the wife's menstrual cycle
  • respects the unitive and procreative nature of conjugal love

What are the benefits of using NFP?

In NFP both husband and wife are taught to understand and live God's design for married love—this will give them countless blessings! NFP methods promote a holistic approach to family planning which both respects procreation and has the potential to deepen the intimacy of husband and wife.

NFP methods support reproductive health. They are good for the body. The natural methods have none of the harmful side effects caused by contraception, especially chemical contraceptives (e.g., pill, injection, etc.). For the woman, NFP charting can even assist in the diagnosis of underlying medical problems. And, if a couple find they are having trouble conceiving, NFP information can help them pinpoint the most fertile time of the wife's cycle.

NFP methods can be marriage strengthening. NFP relies on couple communication and behavior change. NFP methods require husband and wife to cooperate with each other in the most intimate area of their lives. During times of periodic sexual abstinence, husband and wife live a renewed courtship as they discover non-sexual ways to express their love for each other. On a practical level, husbands are encouraged to "tune into" their wives' cycles, and both spouses are encouraged to speak openly and frankly about their sexual desires, hopes for number of children, and prayerful discernment of God's will for their marriage.

When living the NFP lifestyle, husband and wife learn that they have a shared responsibility for safeguarding God's gifts of human sexuality, marriage and family. They also grow in their understanding of God's will for their family size. NFP has the potential to make good marriages great!

NFP is good for marriage!

  • Supports reproductive health
  • Has no harmful side effects
  • Is environmentally friendly
  • Is inexpensive
  • Cooperates with a couple's combined fertility
  • Is useful to either achieve or avoid pregnancy
  • Can be used throughout the reproductive life cycle
  • Requires shared responsibility and cooperation by husband and wife
  • Fosters mutual communication between husband and wife
  • Encourages respect for and acceptance of the total person
  • Promotes marital chastity
  • Values the child
  • Honors God's design for married love!

How effective are NFP Methods for avoiding pregnancy?

Since NFP methods are not contraception, their effectiveness works both ways—for achieving and postponing pregnancy.

This is important news to married couple because typically "effectiveness" is thought to be "only" related to avoiding pregnancy. In NFP education, both husband and wife learn about their combined fertility and are taught how to live in harmony with God's design. They are also encouraged to discern whether God is calling them to attempt to have a child or to postpone a pregnancy. The methods of NFP are the only approach to true responsible parenthood because they respect God's design 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.

Avoiding Pregnancy

When wishing to avoid pregnancy, studies show that couples who follow their NFP method’s guidelines correctly, and all the time, achieve effectiveness rates of 97-99%.

Others, who are unclear about their family planning intention (i.e., spacing or limiting pregnancy) or are less motivated, will not consistently follow the method’s guidelines and have a lower effectiveness rate of 80-90%.

Where can I learn how to use NFP?

The best way to learn NFP is from a qualified instructor—that is, one who is certified from an NFP teacher training program. Contact your local Catholic diocese (usually the Office of Marriage and Family Life) to find a certified NFP teacher near you (see: Find an NFP Class).

To study a method of NFP in your home, many NFP providers offer distance learning, see: NFP Distance Learning.

For additional NFP information, see: NFP Homepage.


The above questions with their answers are available in a brochure called "Natural Family Planning" (English and Spanish). To order, contact:; or call toll-free at 1-866-582-0943. Ask for publication #9521 for English and #9525 for Spanish.

Hear from NFP leaders and promoters . . .

Damon Owens, Joyful Ever After, speaks with USCCB staff Andrew Bonopane about NFP and married life.

Fr. Dan McCaffrey, NFP Outreach, speaks with USCCB staff Theresa Notare, PhD about his ministry to spread the work about Church teaching on married love and the gift of life and NFP.

Jackie and Bobby Angel, Why we love NFP and Why we hate NFP

Jason Evert provides a lecture on NFP.

Matt Fradd and Jason Evert, NFP is Not Contraception. Watch the entire hour-long episode that discusses other issues that include chastity, dating, and modesty. 

Related topics that explore . . . 

Natural Family Planning, provided by the USCCB's Made for Love podcasts (please note, when in the site, scroll down the list for the numbered episode). Episodes 17 and 18 cover the benefits and challenges of NFP use in marriage in the words of the couples themselves.

Humanae vitae. The papal encyclical, Humanae vitae on its fiftieth year anniversary, provided by the USCCB's Made for Love podcasts (please note, when in the site, scroll down the list for the numbered episode). Humanae vitae teaches about the Church's understanding of married love, God's gift of procreation, the husband and wife's stewardship over these gifts, and the moral regulation of births in marriage. See episodes 15 and 16.

Openness to Life in Marriage. Fr. Mike Schmitz discusses this important reality in marriage.

Visit the USCCB's Made for Love podcasts to listen to discussions about related issues exploring dating, marriage, pregnancy, infertility, family life, and challenges to loving as Jesus calls us to love.