Uterine activity after oral mifepristone administration in human pregnancies beyond 41 weeks' gestation.

BACKGROUND/AIM: 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.

CONCLUSION

Oral mifepristone administration to women with pregnancies beyond 41 weeks increases uterine activity in the absence of externally administered uterotonic agents.