| Description |
With the increased use of contraception during the last decade, couples have been seeking safer and more convenient barrier forms of birth control. The cervical cap, which was used by the ancient Eqyptians and widely used in Europe since 1823, has not been approved in the United States due to lack of recent statistics to verify its safety and effectiveness. In 1979. the Food and Drug Administration published a "Request for Proposals for Use Effectiveness of Cervical Caps" to which the Utah Women's Clinic responded and was granted permission to conduct a clinical trial. A cohort study was begun, from this approved project, to investigate the efficacy of the cervical cap in comparison to the diaphragm as a barrier method of contraception in three areas: 1) adverse reactions and complaints reported, 2) discontinuation rates, and 3) pregnancy rates. The variables of user compliance and the number of previous abortions were also examined for possible effect on contraceptive efficacy. The cohort consisted of women of age 18 who lived in the Salt Lake City area and telephoned the Utah Women's Clinical to request a cervical cap. At the end of the two-year study period, 730 women and requested information about receiving a cervical cap, tu only 371 women were fit with a cap. Questionnaires were completed upon entrance into the study, at one month following the initial visit, and at six-month intervals, thereafter. Diaphragm users - women fit with a diaphragm at the clinic during the same time period - were identified from clinic records and sent a questionnaire similar to the follow-up questionnaire that the cervical cap users completed. Fifty-nine diaphragm users responded to the questionnaire. There were no adverse reactions, symptoms, or complaints reported by any of the women in this study. Due to inadequate questionnaire design, compliance and its effect on contraceptive effectiveness could not be fully analyzed. Discontinuation rates were higher in cervical cap users (40 vs 10 per 1000 woman-months of use, cap vs diaphragm, respectively), although, after adjusting for time the contraceptive method was used, the number of excess cap users that discontinued their contraceptive method compared to diaphragm users was only 7 per 1000 women-years of use. The pregnancy rates were also higher for cervical cap users (19 vs 8 per 1000 woman-months of use, cap vs diaphragm, respectively). After adjusting for the number of previous abortions, cervical cap users were found to have had only 10 excess pregnancies per 1000-woman-months of contraceptive use compared to diaphragm users. Cervical cap users who either discontinued use of their cap or became pregnant were more likely to have had previous abortion than diaphragm users. Although this study encountered some difficulties in design, questionnaire design, and sample size, the results support the data that the cervical cap is as safe and effective as the diaphragm as a contraceptive. |
