November 28, 2018

Editor’s Note: The Institute for Reproductive Health (IRH) at Georgetown University Medical Center has contributed to family planning research since 1985, when it was founded to address family planning gaps around the world. Last month, researchers from the Institute published preliminary research[i] findings suggesting their Dot fertility app may be as effective as some modern fertility awareness based methods (FABMs) of family planning “for avoiding an unplanned pregnancy.” The study is ongoing, and we look forward to the findings once all data is collected and reviewed. We will summarize what we know about Georgetown’s dynamic app in an upcoming blog post.

Beyond this promising new technology, the IRH has helped develop effective modern calendar methods of family planning based on equally solid research. This week we share a medical student’s summary of research[ii] published in 2000 about one such simple, inexpensive natural method of family planning that was highly acceptable among users. The title of the article published by Burkhart et al is “Effectiveness of a Standard-Rule Method of Calendar Rhythm Among Mayan Couples in Guatemala.” The authors report the successful use of a standardized modern calendar method in a developing country.

The contrast between a fertility app and a modern calendar-based method might seem like a clash of two worlds, but it’s not necessarily that way at all. In 2018, a woman’s family planning and health monitoring toolkit includes the versatility and simplicity of FABMs as well as technological advances like fertility apps. The contrast merely highlights that women’s reproductive health needs around the world can be met in many different ways—as individual as the women who use the various methods and resources! In the end, what we hope for is greater access to safe, effective methods that are acceptable and feasible for a variety of women and couples regardless of culture, socioeconomic reality, and the many factors that influence how a woman experiences the challenges and benefits of her fertility.


The Standard Days Method was created by Georgetown University’s Institute for Reproductive Health as a natural family planning method based on a standard period of potential fertility that begins on a specified date in the woman’s cycle and continues for a set number of days. A simplified version of the Standard-Days Rule, which states that the potential window of fertility begins on the 9th day of a woman’s cycle and continues until the 19th day, was applied in this study.

The study was a non-comparative, multi-center prospective clinical trial. Participants were enrolled between mid-March and early July 1998. The couples were from the Guatemalan highlands, and instruction and data collection was completed in five community centers run by small, indigenous nongovernmental organizations.

The selection criteria for women included ages 18-39, having regular menses, and a desire to avoid pregnancy for 12 months. Males in the study must have expressed interest in using the method and a willingness to participate in at least one instruction session. Both partners needed to be willing to abstain from vaginal intercourse for 11 days during each cycle. Instruction took place during a woman’s menses, was completed in either Spanish or one of three appropriate Mayan dialects, and regular follow up occurred during the 12 months of the study.

In order to utilize the method, couples were taught how to use a necklace with beads and a calendar. The necklace contained 30 beads. The first bead was red (indicating initiation of menses), beads 2-8 were brown (indicating infertility), beads 9-19 were green (indicating fertility), beads 20-30 were brown, and a marker would move along the necklace to indicate the current day in the cycle. Couples were instructed to abstain from vaginal intercourse during days 9-19, which were marked by green beads. A calendar was provided for charting the first day of menses and served as a back up if the couple forgot to move the marker on the necklace.

A total of 301 couples were selected for the study, and nearly all of the participants were Mayan. Of the 301 couples, 242 (79%) continued for a full year, 32 stopped using the method because of pregnancy, 31 discontinued for other reasons, and 2 couples were lost to follow-up. The 31 couples that discontinued did so for personal reasons (45.2%), migration (22.6%), desire for pregnancy (16.1%), separation/death of a spouse (9.7%), or a medical condition (6.5%).

A significant finding was that successful completion of the study increased as the woman’s age increased from younger than 20 to 35-39. Similarly, the only demographic factor that was significantly associated with pregnancy was younger age. Level of literacy did not impact the ability to participate and complete the study. All the couples that completed the 12-month study said they would not only recommend the method to others but also continue using the method. A total of 242 couples completed 12 months utilizing the Standard-Rule method, and the cumulative pregnancy rate was 11.2%. After one year of use of the method, the couples were highly satisfied with this approach to family planning.

The strengths of this study include the sample size, percentage of participants who completed the 12-month study, and overall affordability and effectiveness of the method. A potential weakness is the study’s generalizability, since regular follow-up with instructors may have increased participant adherence to the method. A possible confounding variable was that 2/3 of women were breastfeeding when they enrolled in the study, and breastfeeding may have some protective effect against pregnancy even after resumption of menses. While this may have played a role in pregnancy prevention, the one-year pregnancy rate did not differ significantly between women who were breastfeeding and those who were not.

All women included in this study were at least 18 years old and younger than 40. According to the authors, “the only characteristic that was significantly associated with pregnancy was younger age.”  The youngest couples had the lowest success rates in preventing pregnancy and are, thus, likely not suitable candidates for this method. On the other hand, women ages 35-39 (20% of study participants) had the lowest pregnancy and discontinuation rates. Therefore, according to this study, older women (at least through age 39) are likely good candidates to use the Standard Days Method to prevent pregnancy among Mayan couples.

Author Bio: This summary of research findings was written by a male medical student who completed our elective, Fertility Awareness for Women’s Health and Family Planning. We are delighted to educate both female and male students from any medical professional training program through our elective so they can empower more women and couples with knowledge about their fertility.


[i] “Early Study Results Suggest Fertility App as Effective as Modern Family Planning Methods.” EurekAlert!, Georgetown University Medical Center, Oct. 2018,
[ii] Burkhart, Marianne C., et al. “Effectiveness of a Standard-Rule Method of Calendar Rhythm Among Mayan Couples in Guatemala.” Guttmacher Institute, International Family Planning Perspectives, Sept. 2000,



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