The Standard Days Method is a fertility awareness-based method of family planning in which users avoid unprotected intercourse during cycle Days 8 through 19. A prospective multi-center efficacy trial was conducted to test, in a heterogeneous population, the contraceptive efficacy of the Standard Days Method. A total of 478 women, age 18-39 years, in Bolivia, Peru, and the Philippines, with self-reported cycles of 26-32 days, desiring to delay pregnancy at least one year were admitted to the study. A single decrement multi-censoring life table analysis of the data indicate a cumulative probability of pregnancy of 4.75% over 13 cycles of correct use of the method, and a 11.96% probability of pregnancy under typical use. This article describes the study and the results. Results suggest that despite its requirement that couples modify their sexual behavior when the woman is fertile, the Standard Days Method provides significant protection from unplanned pregnancy and is acceptable to couples in a wide range of settings.
Standard Days Method efficacy contraceptive fertility awareness, fertility awareness based method cycle days 8-19 fertile window, Arévalo Jennings Standard Days Method prospective trial, natural family planning typical use correct use pregnancy rates, Standard Days Method CycleBeads contraceptive efficacy, fertility awareness method 26-32 day cycle length, natural family planning multicenter prospective efficacy trial, calendar-based fertility awareness contraceptive method Bolivia Peru Philippines, periodic abstinence method life table pregnancy probability, fertility awareness contraception developing countries multicenter study
PMID 12057784 12057784 DOI 10.1016/s0010-7824(02)00288-3 10.1016/s0010-7824(02)00288-3 Arévalo et al. 2002, Arévalo 2002
Cite this article
Arévalo, M., Jennings, V., & Sinai, I. (2002). Efficacy of a new method of family planning: the Standard Days Method. Contraception, 65(5), 333-338. https://doi.org/10.1016/s0010-7824(02)00288-3
Arévalo M, Jennings V, Sinai I. Efficacy of a new method of family planning: the Standard Days Method. Contraception. 2002;65(5):333-338. doi:10.1016/s0010-7824(02)00288-3
Arévalo, M., et al. "Efficacy of a new method of family planning: the Standard Days Method." Contraception, vol. 65, no. 5, 2002, pp. 333-338.
To summarize the evidence on typical and perfect-use effectiveness of fertility awareness-based methods for avoiding pregnancy during the postpartum period, whether breastfeeding or not. We conducted a systematic review of studies published in English, Spanish, French, or German by November 2021 in MEDLINE, EMBASE, CINAHL, Web of Science, and ClinicalTrials.gov. Abstract and full text reviews were completed by 2 independent reviewers. Study inclusion: at least 50 subjects who enrolled prior to experiencing 3 cycles after childbirth and were using a specific fertility awareness-based method to avoid pregnancy; unintended pregnancy rate or probability calculated; postpartum amenorrheic and postpartum cycling individuals analyzed separately; and prospectively measured pregnancy intentions and outcomes. Outcomes were abstracted and study quality was systematically assessed by 2 independent investigators. Four studies provided effectiveness data for 1 specific fertility awareness-based method among postpartum individuals. Of these, there were zero high quality, 1 moderate quality, and 3 low quality for our question of interest. Typical-use pregnancy probability for the first 6 cycles postpartum for Marquette Method users was 12.0 per 100 women years (standard error [SE] not reported) and for Billings Ovulation Method users ranged from 9.1 (SE 3.9) for non-lactating women <30 years old to 26.8 (SE 4.6) for lactating women <30 years old. Typical-use pregnancy probabilities for the first 6 months post-first menses for the Postpartum Bridge to Standard Days Method users was 11.8 (95% confidence interval 6.01-17.16) and for Billings Ovulation Method users was 8.5 per 100 women (SE 1.7). The current evidence on the effectiveness of each fertility awareness-based method for postpartum persons is very limited and of mostly low quality. More high quality studies on the effectiveness of fertility awareness-based method in postpartum persons are needed to inform clinical counseling and patient-centered decision-making.
Although postpartum individuals may desire to use fertility awareness-based methods to avoid pregnancy, the evidence of the effectiveness of fertility awareness-based methods in this population is limited. More high-quality studies are needed to inform shared decision-making.
There are couples with unmet family planning needs and couples who do not use any modern method, yet they desire to space or avoid pregnancies. Many of them look for safe and effective options like the natural family planning methods. The Billings Ovulation Method based on single index cervical mucus parameter is one such option. The present multicentre trial conducted in India has shown an encouraging use-effectiveness of the method, indicating method failure as low as 1.5 +/- 0.3 and use-failure 15.9 +/- 0.8 per 100 users at 21 months. The method continuation rates have also been as high as 88.3/100 users at 6 months and 52.0/100 users at 21 months.
Knowledge of the fertile and infertile phases of the menstrual cycle can be applied to conceive or to avoid pregnancy. Fertility intentions and sexual behaviors during the fertile time may influence whether and when pregnancy occurs. The Creighton Model FertilityCare System (CrMS) is a specific system of fertility appreciation used to conceive or to avoid pregnancy. The objective of this paper is to report intentions, behaviors, and pregnancy rates during use of the CrMS among couples who initially intended to avoid pregnancy.Data and methodsWe analyzed a prospective cohort study conducted in 17 CrMS centers across the USA and Canada, following 296 couples for up to one year after onset of initial use of the CrMS to avoid pregnancy. Baseline data included demographics, motivations, and pregnancy intentions for each partner. Couples contributed 2894 menstrual cycles, most of which had data collected (by questionnaires and daily diary) on cycle-specific pregnancy intentions, days of potential fertility, and fertility behaviors. Pregnancies were prospectively actively ascertained. We found a high concordance (91%) in cycle pregnancy intentions between partners. However, 44% of cycles with strong intentions to avoid pregnancy included intercourse on potentially fertile days or days of undetermined fertility status. Across all sensitivity scenarios, cumulative 13-cycle pregnancy rates with cycle intention to conceive ranged from 88.0% to 89.8%, and cumulative 13-cycle pregnancy rates with cycle intention to avoid ranged from 29.1% to 35.3%. In multivariate analysis, baseline motivations and intentions for pregnancy within 2 years were strongly correlated with the likelihood of pregnancy, more so than cycle intentions. The findings suggest that in some populations using natural family planning, baseline motivations and intentions may be more strongly related to pregnancy rates than cycle intentions. Our findings also highlight essential elements for evaluating correct use, including complete recording of intercourse and its timing.
A one-day meeting was held as a pre-conference to the Catholic Medical Association Annual Educational event in 2024. A panel of eighteen physicians, scientists, and researchers involved in NFP work was convened to review the available evidence in four topical areas: (i) evidence for effectiveness of NFP methods to postpone and achieve pregnancy, (ii) evidence for effectiveness in the postpartum and perimenopause transition periods, (iii) evaluate the current state of technology in NFP (specifically app and quantitative hormone monitoring), and (iv) evidence examining the impact of NFP on marital relations. In each topical area, the panel worked to reach a consensus opinion on the currently available evidence and identified priorities for further research. Results from these discussions and a set of priorities for further work are presented here.
An expert panel was convened to review the current evidence supporting use of NFP in various settings, utilization of new technology, and the impact of NFP on marital dynamics. Results from these discussions and a set of priorities for further work are presented here.