The National Catholic Bioethics Center
Natural Family Planning
Prepared
Ethicists of the NCBC
February 2015
by the
“Catholic health institutions may not promote or condone contraceptive practices but should provide,
for married couples and the medical staff who counsel them, instruction both
about the Church’s teaching on responsible parenthood and in methods of natural family planning.”
— USCCB, Ethical and Religious Directives for Catholic Health Care Services, 5th ed. (2009), n. 52.
 Summary 
The United States Conference of Catholic Bishops defines natural family planning and differentiates it from contraception as follows:
Natural Family Planning is the general title for the scientific, natural and moral methods of family planning that can help married couples either achieve or postpone pregnancies. 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! (USCCB, “What Is Natural Family Planning” web page, http://www.usccb.
org/issues-and-action/marriage-and-family/natural-family-planning/what-is-nfp/index.cfm)
Methods of Natural Family Planning and Their Effectiveness
Each NFP method is focused on one or more signs of female fertility. Studies show that couples who want to avoid
pregnancy and follow their NFP method’s guidelines consistently and correctly achieve effectiveness rates of 97 to
99 percent:
• The cervical mucus methods include the “ovulation method,” in which a woman learns how to identify the ­normal,
healthy cervical mucus that indicates the days when sexual intercourse is most likely to result in pregnancy.
• The symptothermal methods involve observing several signs of fertility—such as basal body temperature, cervical mucus, changes in the cervix, and secondary fertility signs—and cross-checking two or more of the signs to
pinpoint ovulation.
• The symptohormonal method also involves observing several signs of fertility and adds the use of an ovulation
predictor kit (OPK) or fertility monitor.
 FAQ 
Question 1. Isn’t the avoidance of pregnancy through NFP contraceptive?
Reply: The intent, at the time that marital consent is exchanged, to use NFP to avoid children throughout all of ­married
life clearly is contraceptive. However, Humanae vitae speaks of the morality of responsible parenthood and the spacing of births:
continued
Defending the dignity of the human person in health care and the life sciences since 1972
2 Natural family planning
If therefore there are well-grounded reasons for spacing births, arising from the physical or psychological
condition of husband or wife, or from external circumstances, the Church teaches that married people may
then take advantage of the natural cycles immanent in the reproductive system and engage in marital intercourse only during those times that are infertile, thus controlling birth in a way which does not in the least
offend the moral principles which We have just explained. (n. 16)
The USCCB further clarifies the difference between contraception and NFP as follows:
When couples use contraception, either physical or chemical, they suppress their fertility, asserting that they
alone have ultimate control over this power to create a new human life. With NFP, spouses respect God’s
design for life and love. They may choose to refrain from sexual union during the woman’s fertile time,
doing nothing to destroy the love-giving or life-giving meaning that is present. This is the difference between
choosing to falsify the full marital language of the body and choosing at certain times not to speak that language. (“Married Love and the Gift of Life,” 7)
Question 2. How is NFP different from the rhythm, or calendar, method?
Reply: NFP is not the same as the rhythm method. The earlier method was developed in the 1930s and was based on
the scientific theory that ovulation could be predicted by calculating previous menstrual cycles. This method did not
take into account the variations in women’s menstrual cycles and so is less effective than NFP. NFP is based on the
unique nature of each woman’s cycle and the signs indicating that unique nature.
Question 3. What resources are available to assist dioceses in cultivating NFP practices?
Reply: A number of successful initiatives are outlined by the USCCB on its “Diocesan NFP Ministry” website. Also,
the USCCB Committee for Laity, Marriage, Family Life and Youth has developed a document titled Standards for
Diocesan Natural Family Planning Ministry (2010) that provides guides for the development of a diocesan NFP
ministry and describes basic program components, including the knowledge and skills of effective NFP teachers. The
USCCB website also contains helpful information about the Billings Ovulation Method Association—USA, Creighton Model FertilityCare, Couple-to-Couple League, Northwest Family Services, and Marquette University’s Institute
of Natural Family Planning.
 Resources 
Paul VI, Humanae vitae (July 25, 1968), Vatican website.
USCCB, “Diocesan NFP Ministry” website, http://www.usccb.org/issues-and-action/marriage-and-family/natural-family
-planning/diocesan-ministry/index.cfm.
USCCB, “Natural Family Planning” website, http://www.usccb.org/issues-and-action/marriage-and-family/natural-family
-planning/index.cfm.
USCCB Committee for Pro-Life Activities, “Married Love and the Gift of Life” (2006), http://www.usccb.org/issues
-and-action/marriage-and-family/natural-family-planning/catholic-teaching/upload/Married-Love-and-the-Gift-of
-Life-New-USCCB-Website.pdf.
The National Catholic Bioethics Center
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