The Importance of Effectiveness Studies in Fertility Awareness-Based Methods and the Medical Community

Clinical trials and research studies on Fertility Awareness-Based Methods (FABMs) are scarce, having a few published in peer-reviewed journals in 2018-19, compared to the hundreds of studies published about contraception and contraceptive methods during the same time. In September 2018, the latest and most needed systematic review on the “Effectiveness of FABMs for Pregnancy Prevention” (Peragallo Urrutia et al., 2018) was published in the Journal of Obstetrics and Gynecology. The principal investigator, Joseph Stanford, MD, was a distinguished guest at our monthly webinar series. Dr. Stanford is a professor of family medicine, pediatrics, obstetrics, and gynecology and the director of the Office of Cooperative and Reproductive Health at the University of Utah School of Medicine.

In his talk, Dr. Stanford described the general concepts of pregnancy rates (“pregnancies/cycles”), effectiveness (“1-pregnancy rate”), perfect use, typical use, achieving-related behavior, and avoiding-related behavior in the context of FABMs. He brought clarity on the often-confused terms: perfect use and typical use. He explained that “perfect use is equal to the pregnancy rate for ‘perfect’ use to avoid pregnancy and in which only the cycles with ‘correct use’ to avoid pregnancy are included,” and “typical use is equal to the pregnancy rate for ‘real-life’ conditions to avoid pregnancy, in which all the cycles to avoid pregnancy are included.”

In this systematic review, the research team wanted to answer the question: “What is the evidence of effectiveness of specific FABMs to avoid pregnancy, as measured by unintended pregnancy rates?” To address that question, they formed a multidisciplinary team, registered their protocol in PROSPERO, an international prospective register of systematic reviews, and searched databases such as MEDLINE, Embase, CINAHL, and Web of Science. Besides, they adapted 13 quality criteria and categorized their results as high, moderate, and low indicators. They initially identified 9,868 records, and after exclusions, only 53 unique studies that described 65 cohorts of specific FABMs were included. Of those, fourteen studies evaluated the Billings Ovulation Method or variants (Peragallo Urrutia et al., 2018). According to their classification, five out of 14 were of moderate quality. Of note, none of the studies included in the systematic review had a high-quality score. In the studies of moderate quality, for the Billings Method, the perfect use pregnancy rate per 100 women-years described was 1.1 (Bhargava, Bhatia, Ramachandran, Rohatgi, & Sinha, 1996) and 3.4 (Trussell & Grummer-Strawn, 1991). The lowest typical use pregnancy rate per 100 women-years described was 10.5 (Bhargava, Bhatia, Ramachandran, Rohatgi, & Sinha, 1996), and the highest pregnancy rate was 33.6 (Medina, Cifuentes, Abernathy, Spieler, & Wade, 1980).

In his talk, Dr. Stanford mentioned that the most commonly met high-quality criteria were the type of FABM used, the duration of the study, and the characterization of the population of new users. The high-quality criteria least commonly met were the evaluation of intercourse in each cycle, the close follow-up to detect pregnancy, the reproductive characteristics of the users, and the assessments of intentions for avoiding or achieving pregnancy during each cycle. Therefore, as Certified Billings Teachers and Supervisors, we may want to pay more attention to these features when evaluating clients.

Dr. Stanford’s closing recommendations of reporting all pregnancies (unintended and intended); measuring intentions and different behavioral, demographic, and reproductive characteristics; evaluating all cycles and not only the pregnancy cycles; describing unintended pregnancies as a range; assessing any use of barriers or withdrawal; etc. not only seeds the curiosity in scientists to explore further hypotheses but set the grounds for building best practices to develop meaningful research protocols  that ultimately might help the Billings community, users and providers alike.
 
References:

Bhargava, H., Bhatia, J.C., Ramachandran, L., Rohatgi, P., & Sinha, A. (1996). Field trial of billings ovulation method of natural family planning. Contraception, 53, 69-74.

Medina, J.E., Cifuentes, A., Abernathy, J.R., Spieler, J.M., & Wade, M.E. (1980). Comparative evaluation of two methods of natural in Columbia. Am J Obstet Gynecol, 138, 1142-7.

Peragallo Urrutia, R., Polis, C.B., Jensen, E. T., Greene, M.E., Kennedy, E., & Stanford, J.B. (2018). Effectiveness of fertility awareness-based methods for pregnancy prevention: a systematic review. Obstet Ginecol, 132, 591-604. doi: 10.1097/AOG.0000000000002784

Trussell, J. & Grummer-Strawn, L. (1991). Further analysis of contraceptive failure of the ovulation method. Am J Obstet Gynecol, 165, 2054-9.