CALENDAR RHYTHM EFFICACY - A REVIEW

Objective: To estimate the unplanned pregnancy rate of calendar rhythm . Design: Meta-analysis of eight studies of calendar rhythm published between 1940 and 1989. Results: There exist few studies of the calenda r rhythm method. Analysis of the best of these studies resulted in a c onservative estimated Pearl rate of 18.5 +/- 1.8, and a less conservat ive estimate of 15.0 +/- 4.0, standardized to 12 months' observation; these results are in the range of other natural and barrier methods. D iscussion: We need properly done clinical trials of the calendar rhyth m method to scientifically establish its effectiveness.