Postcoital contraception with levonorgestrel during the peri-ovulatory phase of the menstrual cycle. Task Force on Post-ovulatory Methods for Fertility Regulation. Prospective study of contraception with levonorgestrel. Results of a multicentre trial of Postinor. The use of progestogens as postcoital oral contraceptives. Evaluation of d-norgestrel 1.0 mg as a post-coital contraceptive. Further experience with quingestanol acetate as a postcoital oral contraceptive. Post-coital contraception with dienoestrol. Low-dosage oral progestogens to control fertility. I. clinical investigation. [Postcoital contraception].
The contraceptive efficacy and side effects of postcoital levonorgestrel used repeatedly during the peri-ovulatory period of one cycle was examined in 259 women. All subjects were of proven fertility in their present union and had ovulatory cycles as assessed from pre-treatment BBT charts. The mean number of coital acts during the treatment cycle was 7.5 (SD:2.6) and the mean number of 0.75 mg levonorgestrel tablets taken during the peri-ovulatory period was 4.0 (SD:1.2). Two pregnancies, both considered to be method failures, occurred, giving a failure rate of 0.8% per treated cycle. Although the overall effect of levonorgestrel on menstrual cycle length was small and insignificant, menstrual cycle disturbances were not uncommon. Intermenstrual bleeding or spotting occurred in 8.5% of the treated cycles and 12.5% of the cycles were less than 20 or more than 35 days. Other side effects, mainly nausea, headache and dizziness, were reported by about 20% of the subjects but the apparent incidence of these complaints varied markedly between the nine participating centres from 0% to just over 50%. The data suggest that repeated postcoital use of levonorgestrel is probably not a viable approach to fertility regulation for the majority of women who have regular intercourse and wish to limit the number of their pregnancies. nan nan nan Two hundred and ninety-eight women were followed for 2578 months (2739 'bleeding intervals') of treatment with d-Norgestrel 1.0 mg given as a post-coital oral contraceptive. Fourteen pregnancies were recorded (general failure rate, 6.5 per 100 woman/years); at least 6 of these patients did not miss any tablet (corrected failure rate, 2.8). The acceptability rates (life table method) were 0.58 and 0.40 after 6 and 12 months of follow-up. The most important medical reason for drop-out was cycle irregularities. The cycle pattern is deeply disturbed by this method of oral contraception. nan nan nan nan
The studies of pericoital LNG regimens provided promising results but had a number of serious methodological limitations. A pressing need exits to conduct a rigorous research to confirm the efficacy and safety of pericoital use of LNG as a primary means of contraception among women with infrequent intercourse. If the method is shown to be efficacious, safe and acceptable, the results may warrant revision of the current WHO recommendations and marketing strategies.