By Ori Barashy
A Note from the FACTS Elective Course Director, Dr. Marguerite Duane: In 2010, I had the opportunity to teach a small group of Georgetown medical students about the various methods of natural family planning (NFP). Since I was not very familiar with the Marquette Model , I was delighted when Dr. Fehring, who developed the Marquette Model, graciously agreed to fly to Washington, DC to provide an overview of this method and the evidence for its effectiveness. Since then, he has continued to serve as a friend and mentor, demonstrating the importance of ongoing research to add to the growing body of science supporting NFP.
Editor’s Note: The research article by Fehring and Schneider [1] summarized below was published in 2014. Ori Barashy reviewed and summarized the article while on the FACTS elective in fertility awareness still taught through Georgetown School of Medicine. More than 1,000 medical students and residents have learned about fertility awareness-based methods and NFP through this evidence-based elective, and FACTS will soon launch the first-ever fellowship in restorative and integrative reproductive medicine.
Introduction
In the 2014 article [1] summarized below, Fehring and Schneider compared abstinence and coital frequency between two natural methods of family planning. At the time, it was estimated that only one in one thousand women of reproductive age in the United States used fertility awareness-based methods (FABMs) of family planning. The authors hypothesized that periodic abstinence requirements and the fear of unintended pregnancy explain some of the lack of use of FABMs, as most methods require two weeks or more of abstinence per cycle. A potential solution to this issue was developed in part by the lead author, Dr. Richard Fehring. The proposed system combines electronic hormonal fertility monitoring (EHFM) and cervical mucus monitoring (CMM) to estimate the fertile window. The study [1] compared the estimated fertile window and the frequency of intercourse in couples using the two different methods of monitoring.
Methodology
Data for this study was acquired from a prior study comparing the efficacy of EHFM and CMM. For EHFM, the ClearBlue Easy Fertility Monitor (CBFM) was used. Inclusion criteria for female partners included: age 18 to 42 years, stated menstrual cycle range of 21 to 42 days, and no history of hormonal contraceptives in the previous three months. Additionally, for participants who had been breastfeeding recently, at least three cycles had elapsed after weaning.
The CBFM detects rising levels of urinary estrone-3-glucuronide (E3G) and is reportedly 98.8% accurate. It requires the user to indicate her first day of menses, after which the monitor will request 10 to 20 (once daily) urine tests per cycle. The monitor then qualitatively indicates “low,” “high,” or “peak” fertility.
“The CBFM detects rising levels of urinary estrone-3-glucuronide (E3G) and is reportedly 98.8% accurate.”
CMM participants were asked to observe their cervical mucus and rate it as “low,” “high,” or “peak” based on visual description. All participants used an online chart to record their fertility observations, coital acts, and menstrual bleeding. The charting system automatically indicated the fertile window based on the fertility algorithm. All participants were instructed to avoid any genital contact during the estimated fertile window, and to refrain from intercourse on all “high” and “peak” days. Data were analyzed using the Statistical Analysis System and the Statistical Package for the Social Sciences software systems.
Results
The study participants recorded a total of 1,663 menstrual cycles: 1,027 for the EHFM group and 636 for the CMM group. There were no significant differences between the two study groups on demographic variables.
Researchers compared the estimated fertile window between the two methods. Across all 12 months, the estimated fertile window showed no significant difference between the two methods, although CMM had significantly fewer fertile days in the first six cycles, and EHFM had significantly shorter estimated fertile window in the latter six cycles.
The authors also compared the frequency of intercourse per menstrual cycle between users of EHFM versus CMM. Participants in the EHFM group reported significantly more instances of intercourse than the CMM group across the entire study, although the significance only appeared after the first six cycles.
Discussion
Overall, there was no statistically significant difference in the estimated fertile window length between these two FABMs. It was hypothesized that a shorter estimated fertile window would lead to more frequent coital acts, thus similar fertile windows should result in similar coital frequency. It was observed that despite similar estimated fertile windows, couples using EHFM engaged in sexual acts more frequently. This may be explained by couples feeling more confident in the objectivity of the monitor relative to the perceived subjectivity of CMM. This notion is supported by the fact that coital frequency increased in the EHFM group after the first six cycles of use, at which point the monitor becomes more accurate.
“Despite similar estimated fertile windows, couples using EHFM engaged in sexual acts more frequently. This may be explained by couples feeling more confident in the objectivity of the monitor relative to the perceived subjectivity of CMM.”
Based on this study data, the estimated fertile window of both systems was around two weeks per cycle. For couples interested in these family planning methods, it is important to recognize that a woman’s fertile window is only a few days per cycle, but it can be difficult to pinpoint those days, as these methods estimate a range of time where the actual fertile window likely occurs.
“For couples interested in these family planning methods, it is important to recognize that a woman’s fertile window is only a few days per cycle.”
Notably, the range of body mass index (BMI) in the CMM group was much wider than that of the fertility monitor group. There was also a large discrepancy between the number of cycles recorded by the two groups. Additionally, the high percentage of White and religious participants raises questions as to the generalizability of this study.
The study was further limited by its inclusion and exclusion criteria. “Regular cycle” was defined generously as 21 to 42 days because that is the range of the ClearBlue monitor; this may have given that group an advantage. The research also excluded women who were recently postpartum or breastfeeding as well as women over 42 years of age. Further research may be needed to compare these two FABMs in women who were excluded from this study.
References
[1] Fehring, Richard J., and Mary Schneider. “Comparison of Abstinence and Coital Frequency between 2 Natural Methods of Family Planning.” Journal of Midwifery & Women’s Health , vol. 59, no. 5, Sept. 2014, pp. 528–532., https://doi.org/10.1111/jmwh.12216
ABOUT THE AUTHOR
Ori Barashy is a fourth-year medical student at the California University of Science and Medicine in Colton, CA. He completed his undergraduate education at Chapman University in Orange, CA. He plans to do his residency in internal medicine and is interested in health education. Barashy enrolled in the FACTS elective to gain a better understanding of natural family planning methods and effective ways to share these methods with interested patients, friends, and family.
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