Comparative evaluation of two methods of natural family planning in Columbia

Results of a comparative study of the ovulation method (OM) and symptothermal method (STM) of natural family planning in Colombia are presented. Recruitment of volunteer couples began in August, 1976, and continued through December, 1978, during which time 566 couples were randomly assigned to one or the other of the two methods. The study included 3 to 5 months of training in the method assigned, after which the couples entered the follow-up phase of the study. They remained in follow-up until (1) they dropped out or (2) the study closed in June, 1979. Total dropout rates were high for both methods of natural family planning. One year after entry into the follow-up phase of the study, net pregnancy rates were 24.2% for OM users and 19.8% for STM users. Gross pregnancy rates were 29.2% for OM and 26.1% for STM. Differences in pregnancy rates between the two methods were not statistically significant.