Level of Evidence = D
The comparative efficacy of fertility awareness-based methods of contraception remains unknown.
A Cochrane review  included three studies with a total of 1866 subjects. Fertility awareness-based methods of family planning involve identification of the fertile days of the menstrual cycle and are called, e.g., rhythm, natural family planning or periodic abstinence methods. Because of poor methods and reporting, pregnancy rates could not be determined. A trial in Colombia found similar numbers of pregnancies among women randomized to the ovulation and symptothermal methods. In contrast, a companion trial in Los Angeles observed more pregnancies in the group assigned to the ovulation method. In the two U.S. trials, recruitment of participants was unexpectedly difficult; this aspect was not mentioned in the report from Colombia. Continuation rates were poor. In the two larger trials, most participants discontinued their assigned method before entering the observation phase of the trial. Comment: The quality of evidence is downgraded by imprecise results (limited study size for each comparison), by limitations in study quality (more than 20% loss to follow up) and by inconsistency (heterogeneity in interventions and outcomes).
Fertility awareness-based methods for contraception is a sample topic found in
To find other Evidence Central topics
please login or purchase a subscription.