Natural Family Planning

REALITY: Natural Family Planning (NFP) is an umbrella term for modern, scientifically accurate, and reliable methods of family planning. It differs significantly from the older Rhythm (or Calendar) Method. The Rhythm Method tried to estimate the time of next ovulation by calculating previous menstrual cycles. Although this approach had scientific underpinnings, in practice it often proved inaccurate because of the unique nature of each woman’s menstrual cycle. NFP, by contrast, has been proven scientifically sound in both theory and practice.

NFP is based on scientific research about women’s cycles of fertility. Since the 19th century, doctors have known about the changes in cervical mucus and its relation to fertility. In the 1920s, temperature rules were developed. However, it wasn’t until the 1950s that an educational process was developed to teach the observation and interpretation of these fertility signs.

The NFP methods are: the Creighton Method, which monitors changes in a woman’s cervical mucus; and the Sympto-Thermal Method (STM), which combines observations of temperature and cervical mucus with other indicators such as changes in the cervix and secondary fertility signs, and the Marquette Method (MM), which is an algorithm-based method which measures a woman's hormone levels by ovulation test sticks and a digital monitor.

REALITY: The natural methods do not depend on having regular menstrual cycles; they treat each woman and each cycle as unique. NFP works with menstrual cycles of any length and any degree of irregularity. It can be used during breastfeeding, just before menopause, and in other special circumstances. NFP allows a woman to understand the physical signals her body gives her to tell her when she is most likely to become pregnant. Once she understands this information, she and her spouse can use it according to their family planning intentions.

The natural methods can be used throughout a woman’s reproductive life. These methods are progressive. That is, they monitor the current, day-to-day signs of the woman’s cycle. Instruction in NFP provides couples with information about their bodies that is specific and observable. When special circumstances do occur, a woman can contact an NFP instructor for additional guidance in interpreting her signs of fertility.

REALITY: Anyone who is taught by a certified teacher and motivated to use NFP can do so. The methods are so simple that they have been successfully adapted to suit the needs of countries all over the world – first world countries and third world countries; those with many years of education, and those who are illiterate.

In a World Health Organization (WHO) study, 725 couples from five countries – El Salvador, India, New Zealand, Ireland, and the Philippines – were taught the ovulation method of NFP over the course of three months. After a year the couples were evaluated, and the method effectiveness rate was 97.2%. Note: half of the Salvadorean couples were illiterate, proving that an advanced education is unnecessary for learning NFP effectively.

REALITY: The effectiveness of NFP depends upon spouses’ following the rules of the method according to their family planning intention (i.e. achieving or limiting pregnancy). When couples understand the methods and are motivated to follow them, NFP is up to 99% successful in spacing or limiting births.

When comparing family planning methods, researches distinguish between “perfect use” – when a method is used consistently and correctly every single time – and “typical use” – or the success rate for all people using the method, no matter how precisely or consistently they use it. As the chart below demonstrates, NFP is just as effective at preventing pregnancy as other common family planning methods, particularly when it is used consistently and correctly.

NFP / sympto-thermal (perfect use): 99.6%
NFP / sympto-thermal (typical use): 89%

The Pill (perfect use): 99.7%
The Pill (typical use): 92%

Condoms (perfect use): 98%
Condoms (typical use): 85%

Withdrawal (perfect use): 96%
Withdrawal (typical use): 73%

REALITY: Most people most of the time are not engaged in sexual activity (see table). If couples who practice NFP were to engage in intercourse on all the days when abstinence is not required for spacing births, they would be doing so at a rate almost twice the national average!

Average monthly coital frequency among both married and unmarried couples in the United States:

Age: Average
Frequency:
18-24 8
25-34 9
35-44 8
44-55 7
55-67 5

If wishing to avoid pregnancy, a couple practicing NFP is usually advised to abstain from intercourse and genital contact during the wife’s fertile time. NFP couples can make love no less frequently in each cycle than other couples.

REALITY: NFP methods are different from and better than artificial contraception because they:

• Follow God’s design for sexuality as both love-giving (unitive) and life-giving (pro-creative).
• Are moral and in line with Catholic teaching (contraception is considered a serious sin).
• Foster respect for and acceptance of the total person.
• Cooperate with, rather than suppress, a couple’s fertility.
• Can be used both to achieve and avoid pregnancy.
• Call for shared responsibility and cooperation by husband and wife.
• Inspire spousal communication.
• Have no harmful side effects.
• Are virtually cost free.

REALITY: In fact the Church encourages people to be responsible stewards over their fertility. In this view of “responsible parenthood” married couples carefully weigh their responsibilities to God, each other, and the children they already have when making decisions about the number and spacing of their children.  Couples who prayerfully discern that they have a serious reason to avoid pregnancy can make use of NFP to do so.  In fact, that is why Natural Family Planning was developed in the first place!  (For more on “serious reasons” see CCC 2368, USCCB, and EWTN.)

The nature of both marriage and sexual intercourse are life-giving (pro-creative) and love-giving (unitive).  This reflects the Divine plan. That is why the Church teaches that couples must not actively separate their fertility from their sexual union (e.g. by using contraceptives). To do so is to show disrespect for an important gift of the Creator, a gift that is intrinsically bound with the unitive nature of marital love.

REALITY: The Church wants married couples to have the best sex possible! Remember, there is a difference between simply “having sex,” which includes actions directed towards the self, and “making love,” which requires the giving of self to the other. Only in a lifelong, committed, loving relationship, centered in Christ, can couples hope to fully experience the sacrament of life and love, i.e., marriage.

Current studies confirm what the Church has always taught: married sex is more fulfilling and enjoyable than uncommitted sex. People who “use” sex only for their own pleasure end up using other people–and they lose the real joy of sexuality. Unconditional love is what marriage is all about. That love is a real source of joy in the lives of married couples!

[1] From Dr. Richard Fehring, Marquette University, who adapted it from—Trussell, J.  “Contraceptive failure in the United States.”  Contraception.  2004; 70:89-96.

*All Myth + Reality information comes from the Diocese of Harrisburg: https://www.hbgdiocese.org/marriage-and-family/natural-family-planning/#myths-realities-nfp