Safety and effectiveness of hormonal postcoital contraception: a prospective study

The aim of this study was to evaluate the demographic characteristics of the population attending our hospital requesting postcoital contraception and to determine the effectiveness of the method and its side-effects.

A total of 503 women asking for postcoital contraception were included in a prospective open trial. After filling in a questionnaire dealing with demographic and contraceptive data, we prescribed an ethinylestradiol-levonorgestrel combination (100 micrograms/500 mg for two doses 12 h apart).

Only 487 women were available for analysis of demographic data. A further 77 were excluded because they presented irregular menstrual cycles and 55 cases were lost for follow-up. Mean age was 22.6 +/- 5.25 years and 35.9% of cases came to the center within the first 5 h after unprotected intercourse. Only 18.8% had previously asked for postcoital contraception. Breakage of condom was the most common reason for request (81.9%). Two pregnancies occurred in the remaining 355 women. According to Dixon's method 15.5 pregnancies should be expected being the overall efficacy of 87.14%. There were no serious adverse effects. Nausea and vomiting (16.33%) were the most prevalent and 59% of the users menstruated at the expected time whilst menses were delayed in 6% of the cases.

The combination of ethinylestradiol and levonorgestrel in low doses is an effective and safe method of postcoital contraception.