Why does the CDC insist on alternative facts about natural family planning?

Carolyn Moynihan
May 5, 2017
Reproduced with Permission

Although family planning looms large in economically developed, low fertility countries, not all couples approach the timing and spacing of children in the same way. In the majority of cases the wife or female partner will use chemical methods like the pill or IUD, despite side effects that can be quite burdensome and even pose serious health risks.

What the vast majority of couples do not know is that these burdens and risks are not necessary in order to delay a pregnancy. If "effectiveness" is their priority, they should know that fertility awareness based methods (FABMs) are at least as effective as the contraceptive pill.

But they don't, because most medical professionals, along with prominent websites on women's health and reports in the media, generally discount this option, believing that FABMs have a 24 percent "failure" rate - that is, 24 unintended pregnancies per 100 women in the first year of typical use.

According to experts in the field, this figure is nowhere near the truth, which is that, even with typical rather than perfect use, today's FABMs have unintended pregnancy rates ranging from about 12 percent to zero. The "24 percent" comes from a very flawed study that the Centers for Disease Control and Prevention - the peak public health agency in the United States - has used since 2011 for ranking the effectiveness of contraceptive methods.

Despite the evidence of more recent, high quality studies and requests to update its information on fertility awareness methods, the CDC has so far not changed the misleading figure.

As a last resort, a public petition has been launched by two organisations: FACTS (Fertility Appreciation Collaborative to Teach the Science) -- a group of family physicians and experts in the field of fertility appreciation, whose co-founder and executive director is Dr Marguerite Duane, an Adjunct Associate Professor at Georgetown University School of Medicine; and Natural Womanhood, a grassroots lay initiative based in San Antonio, Texas, and led by Gerard Migeon.

Dr Duane is the lead author of a 2013 review of four different types of the most popular of these methods. Drawing on this, and another (PDF) recent study from Marquette University, she says:

"Based on the most up-to-date and highest quality published medical research, the effectiveness rates of Fertility Awareness Based Methods (FABMs) with correct use are between 95 and 99.5%, depending on the method. Even with typical use, the effectiveness rates of FABMs are comparable to most commonly used forms of birth control."

The precise data are as follows:

Sympto-thermal Method: pregnancy rate with perfect use 0.4%, with typical use 1.6%

Marquette Method: pregnancy rate with perfect use 0%, with typical use 6.8%

Billings Ovulation Method®: pregnancy rate with perfect use 1.1%, with typical use 10.5%

Standard Days Method: pregnancy rate with perfect use 4.8%, with typical use 11.9%

Obviously, these unintended pregnancy rates are far from the 24 percent rate given by the CDC.

That figure comes from James Trussell, a well-known contraception researcher, in a chapter in Contraceptive Technology: Twentieth Revised Edition ( New York, 2011). His methodology results in two kinds of bias:

First bias: The effectiveness rates are based on retrospective surveys. Specifically, in 1995 and 2002, the research team surveyed about 18,000 women and asked them to recall the method of birth control they were using when they got pregnant. Recall is a weak measure. The respondents could have used a mix of methods. Any description that sounded like a fertility awareness method was put in the "periodic abstinence" group.

Second bias: The authors put much older, low-tech methods, including the calendar rhythm method, in the same basket as modern, standardized, and proven Fertility Awareness Based Methods such as the Sympto-Thermal and Ovulation methods. In fact, 86% of those whom the study identified as FABM users stated they used the calendar rhythm method - a much older and less effective method developed in the 1930s - as their primary form of contraception. But lumping together old and new natural methods masks important differences in their effectiveness, a fact acknowledged by the author of the study. It would be akin to putting all progesterone methods like the Mirena IUD and the mini-pill in the same category and then classifying them as having one lower effectiveness rate.

In April last year the prestigious American Academy of Family Physicians (AAFP), which represents over 120,000 members, wrote an official request to the Department of Health and Human Services asking that the effectiveness rating be changed. They wrote:

"Family physicians need accurate data to share with patients who are making family planning decisions. The AAFP would therefore like to request that the CDC update the effectiveness rates quoted for these methods in the 'Effectiveness of Family Planning Methods' resource."

One year later, there has been no public response from the CDC, no apparent action taken to consider the evidence offered by the AAFP.

The worst of this is that women experiencing side effects from hormonal contraception - and these range from mild symptoms, such as nausea, bleeding or breast tenderness, to more severe ones such as an increase risk of blood clots, certain types of cancer or stroke - are not being offered a healthy and effective alternative.

An alternative, moreover, that has many other benefits -- not least, in an era when infertility is increasing, that it can help couples achieve a pregnancy. It also costs much less than contraception; it can improve the couple's relationship; and young women who learn fertility awareness are empowered and gain self confidence and self control.

In their petition to CDC director Dr. Anne Schuchat this week Dr Duane and Gerard Migeon write:

Women and medical professionals deserve accurate information about effective ways to prevent pregnancy based on the best research available. FABMs are increasingly in demand as women seek effective family planning options that are free from hormones and side effects.

Indeed the World Health Organization recognizes that FABMs are the only methods of family planning with no medical side effects.

It has been reported that up to 61% of women say they would be interested in using these methods to avoid pregnancy if they were properly informed about them. Yet only 3 to 6% of medical professionals are aware of the actual effectiveness rates of FABMs. As a result, women may not have access to FABMs.

Only the CDC is in a position to correct this misinformation.

To have the greatest impact they say they need to gather 100,000 signatures. So, consider signing and sharing it with friends and family.