Uterine activity after oral mifepristone administration in human pregnancies beyond 41 weeks' gestation.
OBJECTIVE
To examine the effect of oral mifepristone on uterine activity in postterm human pregnancies.


METHODS
As part of a randomized, placebo-controlled trial comparing 200 mg oral mifepristone to placebo for preinduction cervical ripening in women with well-dated pregnancies beyond 41 weeks' gestation with unfavorable cervices, uterine activity was continuously recorded with external tocodynamometry and contraction frequency tabulated.


RESULTS
Ninety-seven women received mifepristone and 83 women received placebo. Uterine activity (uterine contractions/hour) was greater in the mifepristone than in the placebo group between 7 h (8.03 +/- 0.48 vs. 5.90 +/- 0.39, p = 0.001) and 24 h (8.53 +/- 0.68 vs. 6.61 +/- 0.46, p = 0.02) after dosing.


CONCLUSIONS
Oral mifepristone administration to women with pregnancies beyond 41 weeks increases uterine activity in the absence of externally administered uterotonic agents.
Fassett
Michael J
MJ
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Southern California Keck School of Medicine, Los Angeles, CA, USA. Michael.J.Fassett@kp.org
Wing
Deborah A
DA
D000021:Abortifacient Agents, Steroidal / Q000008:administration & dosage / Q000494:pharmacology*; D000284:Administration, Oral; D000328:Adult; D020070:Cervical Ripening / Q000187:drug effects*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007751:Labor, Induced / Q000379:methods*; D015735:Mifepristone / Q000008:administration & dosage / Q000494:pharmacology*; D011247:Pregnancy; D011273:Pregnancy, Prolonged; D014590:Uterine Contraction / Q000187:drug effects*
D000021:Abortifacient Agents, Steroidal; D015735:Mifepristone