Evaluating Pregnancy Rates in Fertility Awareness-Based Methods for Family Planning: Simulated Comparison of Correct Use to Avoid, Method-Related, and Total Pregnancy Rates.

Fertility awareness-based methods (FABMs), also known as natural family planning (NFP), enable couples to identify the days of the menstrual cycle when intercourse may result in pregnancy ("fertile days"), and to avoid intercourse on fertile days if they wish to avoid pregnancy. Thus, these methods are fully dependent on user behavior for effectiveness to avoid pregnancy. For couples and clinicians considering the use of an FABM, one important metric to consider is the highest expected effectiveness (lowest possible pregnancy rate) during the correct use of the method to avoid pregnancy. To assess this, most studies of FABMs have reported a method-related pregnancy rate (a cumulative proportion), which is calculated based on all cycles (or months) in the study. In contrast, the correct use to avoid pregnancy rate (also a cumulative proportion) has the denominator of cycles with the correct use of the FABM to avoid pregnancy. The relationship between these measures has not been evaluated quantitatively. We conducted a series of simulations demonstrating that the method-related pregnancy rate is artificially decreased in direct proportion to the proportion of cycles with intermediate use (any use other than correct use to avoid or targeted use to conceive), which also increases the total pregnancy rate. Thus, as the total pregnancy rate rises (related to intermediate use), the method-related pregnancy rate falls artificially while the correct use pregnancy rate remains constant. For practical application, we propose the core elements needed to assess correct use cycles in FABM studies. Summary: Fertility awareness-based methods (FABMs) can be used by couples to avoid pregnancy, by avoiding intercourse on fertile days. Users want to know what the highest effectiveness (lowest pregnancy rate) would be if they use an FABM correctly and consistently to avoid pregnancy. In this simulation study, we compare two different measures: (1) the method-related pregnancy rate; and (2) the correct use pregnancy rate. We show that the method-related pregnancy rate is biased too low if some users in the study are not using the method consistently to avoid pregnancy, while the correct use pregnancy rate obtains an accurate estimate. Short Summary: In FABM studies, the method-related pregnancy rate is biased too low, but the correct use pregnancy rate is unbiased.

Fertility Awareness-Based Methods for Family Planning and Women's Health: Impact of an Online Elective.

BACKGROUND AND OBJECTIVES: Fertility awareness-based methods (FABMs) are evidence-based means of tracking observable biomarkers of a woman's fertility for the purpose of reproductive health monitoring and family planning. However, medical education regarding FABMs is limited. The purpose of this study was to examine the effect of a 4-week, two-part online elective on students' knowledge of FABMs, confidence in explaining and offering them to patients, and anticipated behaviors in future practice. METHODS: The online elective, "FABMs for Family Planning and Women's Health," was delivered from August 2020 to May 2023. Students completed pre- and postknowledge surveys. Paired t tests and the Wilcoxon signed rank test were used for analysis of the data. RESULTS: A total of 571 students completed the elective, and 462 students completed both pre- and posttest surveys (response rate=81%). Students' knowledge of FABMs increased significantly. Posttest scores increased by a mean of 9.02 for Part A and 5.95 for Part B. We identified a significant increase in students' confidence discussing FABMs to avoid pregnancy, achieve pregnancy, monitor reproductive health, and address reproductive health concerns. At the completion of the elective, students were significantly more likely to offer FABMs as an option for most or all women. CONCLUSIONS: This online elective addresses the knowledge gap in FABMs and was effective in improving students' knowledge of FABMs and their confidence and willingness to offer these methods to patients for family planning and management of common women's health conditions.