Late postcoital treatment against pregnancy with antiprogesterone RU 486.
Thirty female volunteers who had experienced an occasion of unprotected intercourse in midcycle were given a single oral dose of 600 mg of RU 486 1 day before the expected onset of menses. Eighteen of them (60%) had conceived, as evident by human chorionic gonadotropin elevation (greater than 2 IU/L). Menstrual-like bleeding was induced in 29 women (97%). Only one woman became clinically pregnant, and this pregnancy was subsequently terminated by vacuum aspiration and curettage. The drug treatment was well tolerated, but it lengthened the post-treatment menstrual cycle on average by 4 days. RU 486 thus may offer an alternative for postcoital prevention of pregnancy if taken before the establishment of menses delay. The lengthening of the first post-treatment cycle may invalidate the use of RU 486 as a regular once-a-month contraceptive.
Lähteenmäki
P
P
Helsinki University Central Hospital, Department of Obstetrics and Gynecology, Finland.
Rapeli
T
T
Kääriäinen
M
M
Alfthan
H
H
Ylikorkala
O
O
D000328:Adult; D003281:Contraceptives, Postcoital / Q000494:pharmacology*; D003283:Contraceptives, Postcoital, Synthetic / Q000494:pharmacology*; D004963:Estrenes / Q000494:pharmacology*; D005260:Female; D006801:Humans; D015735:Mifepristone; D011247:Pregnancy / Q000187:drug effects*
D003281:Contraceptives, Postcoital; D003283:Contraceptives, Postcoital, Synthetic; D004963:Estrenes; D015735:Mifepristone