A review of fertility awareness based methods of birth control

Thesis (M.A.)--Boston UniversityWomen who are interested in controlling the timing of their pregnancies have many birth control and family planning options. The majority of women use exogenous forms of contraception, including oral contraceptive pills, hormone shots or patches, intra-uterine devices, or barriers such as condoms, sponges or diaphragms. Many of the exogenous methods have negative side effects including allergic reactions and increased risk of blood clotting, and cancer. Additionally, there can be religious objections to these methods. In an attempt to provide women other, natural, birth control options, an array of methods have been developed over time using knowledge of a woman's menstrual cycle.These methods are referred to as fertility awareness based methods because they track various symptoms of a woman's menstrual cycle to determine when she is fertile. Changes in the cervix, cervical mucus secretions, and basal body temperature indicate the fertile window when a woman is most likely to get pregnant. To avoid pregnancy, women using fertility awareness based methods abstain from unprotected intercourse during their fertile windows. Using cycle length and observed physical changes, six methods have been developed. The goal of this thesis is to review and compare the methods. Of the developed methods, the Standard Days method is a calendar method with an average method effective rate of 95% and an average typical-use effective rate of 88%. The Billings Ovulation method, a cervical mucus only method, has an average method effective rate of 98.5% and an average typical-use effective rate of 82%. The Creighton Model of Fertility Care System, also a cervical mucus only method, has an average method effective rate of 99% and an average typical-use effective rate of 87%. A simpler, cervical mucus only method is the TwoDay method which has an average method effective rate of 96% and a typical-use effective rate of 91%, higher than the other cervical mucus methods, likely due to its ease of use. The symptothermal method uses a combination of symptoms to create a double-check system for entering and exiting the fertile window. The method effective rate is the highest at 99.5% and the average typical-use effective rate is 95%. This method is the most effective, but also the most difficult to learn. Finally, the Marquette Model uses cervical mucus and an electronic fertility monitor to indicate the fertile window. The average method effective rate is 97.8% and the average typical-use effective rate is 83%. [TRUNCATED