Proponents of natural family planning (NFP) methods have long claimed that they are good for marriages and that they lower divorce rates. Pope St. Paul VI clearly stated in his 1968 encyclical Humanae Vitae that these methods are consistent with God’s plan for marriage and sexuality. He presciently warned about the use of contraceptives and its effects on society.
Scholars like Robert Michael, Mary Eberstadt, and Mark Regnerus have provided different but complementary expositions of the deep social shift that has taken place since the inception of widely available contraceptives. Robert Michael, an economist from the University of Chicago, has argued that widespread use of contraception was a major cause of the increase in divorce rates between 1960 and 1972. Mary Eberstadt presented the Pill as the technology that facilitated the sexual revolution in her book Adam and Eve after the Pill. Scholar Mark Regnerus, in his 2017 book Cheap Sex, concludes that, along with pornography and online dating, contraception has drastically lowered the access cost of noncommittal sexual activities, thus lessening the motivation for commitment.
As numbers of partners and ease of sexual access have increased with contraceptive availability, marriage rates and even dating have been on a downward trend. By contrast, more than fifty years after Pope Paul VI’s warning about contraception, several compelling studies present new evidence that the practice of Natural Family Planning strengthens marriages.
What Natural Family Planning Is . . .
Natural Family Planning (NFP) is an umbrella term for various methods that teach women to recognize and chart the biological signs of their cycles. Modern methods of NFP provide standardized techniques and tools that allow women to determine what days they are fertile. With this information, couples can choose to have intercourse or not, based on whether they would like to achieve or avoid pregnancy.
It is important to note that women are not always fertile. In fact, they are relatively rarely fertile, as ovulation happens once per cycle and an egg lives only twelve to twenty-four hours. Given that sperm can live up to seven days in a fertile environment, the “fertile window” for couples is around eight days per month, with the two days around ovulation being the most fertile. As a result, a couple that seeks to naturally avoid pregnancy will avoid intercourse for about eight to twelve days each cycle, depending on a number of factors (method used, expertise at charting, women’s regularity, and the clarity of the biological signs the couple monitors).
Modern methods of natural family planning include ovulation methods (Creighton, Billings), sympto-thermal methods (Couple to Couple League, Sympto-Pro), and sympto-hormonal methods (Marquette, FEMM). Each has demonstrated high effectiveness rates both for avoiding and for achieving pregnancy. All of these methods have Catholic roots and are faithful in their teaching to the periodic abstinence approach. In other words, in these methods, couples avoid intercourse during the fertile period.
. . . and What It Is Not
In the past twenty years, other methods and apps have been designed that introduce the use of barrier methods of contraception during the fertile period. This practice makes it possible for couples to have sex during this time even if they want to avoid pregnancy.
In 2018, Natural Cycles became the first FDA-cleared app to function as a natural form of birth control. Developed in Sweden by physicist Elina Berglund and her husband, Natural Cycles boasts a typical effectiveness rate of 93 percent. The app works by monitoring a woman’s basal body temperature to determine her fertile window, during which time it instructs users to “abstain or use protection.”
In March 2021, the FDA cleared another app, Clue Birth Control, which boasts a 92 percent typical effectiveness rate. While Clue, like Natural Cycles, uses algorithmic data to determine a woman’s fertile window, Clue only requires users to input when their period starts—monitoring no fertile signs whatsoever—making it closer to the rhythm method than to modern FABMs. This quality also makes Clue, by its own admission, ineffective for women with irregular cycles. But since Clue also recommends barrier methods such as condoms during its estimated fertile periods, one wonders if much of its effectiveness is based on the effectiveness of condoms (which have a typical effectiveness rate of 87 percent).
Because apps like Natural Cycles and Clue Birth Control suggest the use of barrier methods during fertile periods, adherents of Natural Family Planning do not consider these methods to be true forms of NFP.
The Distinctive Values of NFP
As Birute Obeleniene and her co-authors explain in a February 2021 article in the Linacre Quarterly, in 2001 the WHO replaced the designation of NFP with Fertility Awareness Based Methods (FABMs), embracing the use of condoms as part of the practice of natural methods. The intention was to incorporate NFP methods in “the broad terminology of contraception in terms of logic and values.’”
In truth, argue Obeleniene and her co-authors, the distinctive values of NFP mean that its users have a significantly different mindset and use very different methods than couples who contracept. Thus, NFP is properly understood not as a subcategory of FABMs but as an altogether different approach. The authors argue that “despite the fact that abstinence can be difficult at times, it is the method’s strength.” This practice of self-denial validates that the partners in the marriage are not just “biological social constructs with uncontrollable sexual impulses,” but persons with free will and the ability to grow in virtue and self-control.
Among couples practicing the self-discipline of periodic abstinence surveyed in 2004, women reported feeling more respected and less “used.” A study conducted among German NFP users stated that NFP “improves communication and mutual respect between the spouses.” In the practice of NFP, the sexual relationship of a man and a woman is not a purely biological relationship, but in the terms of Pope Paul VI, “the primary form of interpersonal communion,” underscoring the spiritual dimension of the mutual and total gift of self that is sexuality.
Conversely, the authors explain that “if sexual intercourse does not express a comprehensive human experience but merely a quenching of a sexual desire, then we are talking about the dehumanization of sexual intercourse.” This is what happens when a part of their human reality—the couples’ fertility—is artificially suppressed with contraceptive methods. In such a case, the sexual act is separated from its procreative potential. This separation can harm the relationship, subtly shifting the dynamic to one characterized by what St. John Paul II called “reciprocal consumption.”
The Effects of Periodic Abstinence on Marital Relationships
The effects of NFP use on couples’ relationships were further studied in a new article in the same volume of the Linacre Quarterly, co-authored by Marquette University’s Richard Fehring, PhD, RN, and the Couple to Couple League’s Mike Manhart, PhD. The article offers an extensive literature review of the marital benefits of NFP.
The authors cite several studies conducted among couples who practiced NFP, which show fairly consistent results over the past fifty years. The first such study in 1970 showed that “75 percent of the husbands and 74 percent of the wives felt NFP was helpful to marriage, despite 40 percent of husbands and 22 percent of wives reporting that they had often difficulties with periodic abstinence.” Similarly, a 2016 study among users of the Creighton model of NFP revealed that while “60 percent of respondents stated they sometimes had difficulty with abstinence, 80 percent of men and 85 percent of women felt the use of NFP helped their marriage.”
The most recent such study was conducted in the United States and Western Europe, collecting the 2,560 online surveys from users of two major NFP organizations. The article reports that “64 percent of women and 74 percent of men found that NFP improved their relationship, while less than 10 percent felt the use of NFP had harmed it.” Interestingly, this study mentioned that 47 percent of respondents had previously used contraceptives.
Two studies (Wilson, 2005 and Rhomberg and Weissenbach, 2013) examined the divorce rates among NFP users in the United States and Germany, and both showed a similarly low divorce rate: 3 percent of the 505 US NFP users and 3.1 percent of the 486 German users of the Sympto-Thermal Method. While these divorce rates are very low, the challenge with these studies is that, as the authors note, they are “cross sectional and not population based.” In addition, “other factors could contribute to or prevent divorce,” such as religiosity. Further, the low response rate prevents these studies from being generalizable across a diverse population.
Fehring and Manhart conducted a new study that used the most recent data set of ever-married US women of reproductive age from the 2015–2017 National Survey of Family Growth. One of their goals was to verify whether there would be “greater odds of divorce among those ever-married women who ever used sterilization, the hormonal pill, and condoms as a method of family planning compared to women who never used those methods.” They also wanted to determine if there were “lower odds of divorce among women who ever used NFP, attend church frequently, and feel that religion is important in their lives” compared to those who don’t. Their sample included 2,582 women with a mean age of 36.8 years, 70.8 percent of whom were married and 19.7 percent divorced, 7.8 separated, and 1.7 percent widowed. Not surprisingly, most women reported having used other methods than NFP, while 1 percent reported current use of NFP, and 20 percent had ever used NFP.
Their conclusion shows that marriages fared better among couples who used NFP. For instance, they report that “with ever-use of NFP, 14 percent were divorced or separated, and the rate was 10 percent when excluding the rhythm method users from the sample. In contrast, 39 percent of women who were sterilized and 27 percent of women using the Pill were divorced or separated.”
While this study has obvious limitations, it continues to indicate a significant difference between the relationship outcomes of NFP users and couples who use contraception. As Fehring and Manhart point out, there is a need for more research to understand and establish further the benefits of NFP for marriages, but the initial evidence is compelling.
Could we finally be entering a new, post-Pill era? The voices of women who experienced the long-ignored side effects of hormonal contraception are starting to resonate through the echo chamber of the internet, and spilling over into traditional media. In reading these accounts, one seemingly subjective effect is that women on the pill don’t “feel themselves.” This may be the result of high doses of artificial hormones affecting their moods, perceptions, and reactions to stress, as documented by Dr. Sarah Hill in her recent book This Is Your Brain on Birth Control. One can even speculate, reasonably so, how the Pill affects the way women view their relationships with their partners, to the extent that it could negatively affect their marriage.
We are in the midst of a technology shift that could revolutionize reproductive healthcare and family planning. More than 13 million women use one of the two FDA-cleared apps, Natural Cycles and Clue. That’s more than use the Pill.
Could these methods that allow the use of physical barriers during the fertile window, while not bringing the full benefits of NFP and periodic abstinence, make a difference for couples? Could the experience eventually lead them to practice NFP? In other words, could these clearly insufficient approaches still bring couples closer to the fullness of understanding of their physical relationship? There is hope in the fact that they remove the chemical change women experience on hormonal contraception. Perhaps, either because they dislike the use of condoms or because they realize that avoiding all sexual contact during the fertile period is the most effective way to avoid pregnancy, some couples may come to experience the gift of periodic abstinence.
That’s where promoters of the traditional methods rooted in the Humanae Vitae principles may have a role to play. It’s time to engage these couples, inviting them to explore a better way and giving them the support they need to grow closer through their use of NFP. An active effort to educate and encourage these couples could make an important difference for marriages and families.