By: Daniel Dominguez
Director’s Note: Today, we highlight a study by Arévalo et al that explored the introduction of the Standard Days Method (SDM) to users in Perú.[1] Daniel Dominguez, a recent participant in the FACTS elective, summarized the research, noting patient interest in SDM in areas where other methods of contraception are widely available. Although the design was retrospective, which complicates the accurate assessment of unintended pregnancy rates, high effectiveness rates were observed among study participants. The research findings highlight advantages of making the SDM known and available to women as an alternate option for family planning.
Introduction
Fertility awareness-based methods, or FABMs, are behavioral methods of family planning that often rely on daily observations of signs, such as cervical fluid secretions or basal body temperature, to identify potential fertile days. This information can then be used to pursue or prevent pregnancy depending on one’s goals and desires. The Standard Days Method is a type of FABM in which users avoid sexual intercourse or use barrier methods on days 8-19 of their cycle, the days identified as potential fertile days using this method. Although SDM follows a standard algorithm with fixed fertile days, it can be highly effective when followed with correct use, with studies showing an unintended pregnancy rate of 5 per 100 woman years.[2] Its typical use effectiveness rate is 12 pregnancies per 100 woman years.
“The Standard Days Method is a type of FABM in which users avoid sexual intercourse or use barrier methods on days 8-19 of their cycle, the days identified as potential fertile days using this method.”
Although previous studies have shown the potential benefits of SDM, they were conducted in areas with low contraceptive prevalence rates and in a research setting. The purpose of the 2010 study by Arévalo et al summarized below was to determine the impact of adding regular service SDM to an area in Perú with a high contraceptive prevalence rate. Specifically, the policymakers wanted to know if there would be a significant demand for SDM, if SDM users would be switching away from other modern methods, and whether pregnancy and continuation rates would be within the same range as those observed in the efficacy trial.
Methodology
Arévalo et al conducted a retrospective study in two provinces in the Department of San Martín in northern Perú. This is an area with known high contraceptive prevalence, with up to 49% of women using a modern family planning method. The SDM was added to the method mix offered at the Ministry of Health facilities at these provinces, and it was promoted through strategies proven effective in previous studies. Twenty months after SDM was made available in both clinics, records were used to identify all patients who had opted for SDM. These patients were then contacted and interviewed after giving their informed consent to participate. All pregnancies reported by the participants were included in the efficacy calculations whether the pregnancy was planned, they had stopped using the method, or if the method had been used for less than 6 months.
Results
In total, 1,200 women were interviewed, with a median age of 28. The results established there was a demand for the SDM, with approximately 6% of all family planning patients opting for SDM above other methods. Additionally, most users who adopted SDM did not switch away from another modern method. In fact, they had not been using any reliable form of contraception at the time, with the majority of participants having used unspecified variations of the calendar rhythm (33%).
“The results established there was a demand for the SDM, with approximately 6% of all family planning patients opting for SDM above other methods.”
Out of the 1,200 women who were located and interviewed, 105 (8.75%) had become pregnant while using SDM. The 12-month pregnancy rate was calculated as 10 pregnancies per 100 woman years, similar to the typical use pregnancy rates calculated in the efficacy trial. Of the 105 women who conceived, 83 reported it was a planned pregnancy. Thus, the unintended pregnancy rate of SDM with typical use was 1.8%. Finally, 89% of patients who adopted the SDM were still using it 6 months later, demonstrating a continuation rate greater than that observed in the efficacy trial.
Discussion
With approximately 6% of patients opting for the Standard Days Method, this study demonstrated a high demand for SDM even in settings with high contraceptive prevalence. The high demand for SDM is likely secondary to its ease of use, as it follows a fixed, standard algorithm and does not require patients to check for physical signs of fertility such as cervical mucus, which some women may not be comfortable assessing. Furthermore, since most patients opting for SDM had not been using a modern family planning method, adding the SDM to the mix in a high contraceptive use setting does not appear to compete or subtract from other effective methods but adds to the total modern contraceptive prevalence.
The study also demonstrated pregnancy rates similar to those seen in the efficacy trial and continuation rates even greater than those seen in the trial. Even including the patients who had planned their pregnancy, the SDM still proved to be extremely effective at preventing pregnancy in this study. Although the SDM is simple, it is an effective method that is considered a modern family planning method by the World Health Organization (WHO).
“Even including the patients who had planned their pregnancy, the SDM still proved to be extremely effective at preventing pregnancy in this study.”
Although the continuation rates were higher in this study, it should be noted that in the efficacy trial, 28% of women were switched to another method due to having cycles outside of the recommended 26-32 days, whereas only 7.4% of patients in this study stopped using SDM because of out-of-range cycles. Although the medical professionals and patients were counseled on the SDM, it is possible more patients should not have been using this method due to irregular cycles, which could explain the higher-than-expected continuation rates. However, if there were higher numbers of women with irregular cycles using SDM, one might reasonably expect lower effectiveness rates, which was not the case.
Other limitations of this study include the fact that research personnel were not allowed contact with the medical professionals or SDM clients. Although this reduced bias, it significantly limited the information collected. In this retrospective study, recall bias could have also affected the results, since the women were asked to recall events and their experience with SDM over the previous twenty months. It is possible some pregnancies and other important events were forgotten and not included in the data.
Although this study has some limitations, it is an impressive example of translating research to the public health setting. It demonstrates thoroughly that the SDM is effective even in settings with high contraceptive prevalence and that its introduction to the method mix should be strongly considered.
References
[1] Arévalo, M., Yeager, B., Sinai, I., Panfichi, R., & Jennings, V. (2010). Adding the Standard Days Method® to the contraceptive method mix in a high-prevalence setting in Peru. Revista Panamericana De Salud Pública, 28(2), 80–85. https://doi.org/10.1590/s1020-49892010000800002.
[2] Fertility Appreciation Collaboration to Teach the Science (FACTS). Fertility and Family Planning: The Science behind fertility awareness based methods. Georgetown University. Slide 31.
ABOUT THE AUTHOR
Daniel Dominguez
Daniel Dominguez is a fourth-year medical student at the Nova Southeastern University Dr. Kiran C. Patel College of Allopathic Medicine. He completed his undergraduate education at Florida International University, where he earned a Bachelor of Science in biology. He plans to pursue residency training in diagnostic radiology. He enrolled in the FACTS elective to gain a better understanding of natural family planning methods, in the hope of sharing these methods with future patients or loved ones to help them feel more empowered over their health and reproductive decisions.
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