DOI: http://dx.doi.org/10.18203/2320-1770.ijrcog20210288

Randomized, double-blind, three-arm, parallel-group study to compare the efficacy and safety of a single dose of 100 and 200 mg of mifepristone for cervical ripening in term pregnancies

Leonardo J. Orozco, Silvia Guerrero, Mixel J. Rosales, Jose S. Ramos

Abstract


Background: Mifepristone is an antiprogestin developed to antagonize the action of progesterone by inhibiting its receptors. It has had a recognized role in the medical termination of early pregnancy, reduction in the volume of uterine fibroids and endometriosis symptoms. A new indication for labor induction and cervical ripening in has been proposed. The objective was to compare the efficacy and safety of mifepristone 100 and 200 mg with placebo for cervical ripening in term pregnancies.

Methods: Double-blind, placebo-controlled trial of 90 term pregnancy women randomly assigned to receive orally tablet of 100 mg and 200 mg mifepristone or placebo. Efficacy was assessed by measuring changes in cervical ripening according to Bishop 72 hours after treatment. Statistical analysis was using the t-student test and the chi-square test. The relative risk (RR) was determined with a 95% confidence interval.

Results: The bishop score and the number of contractions at 48 hours in the group of 200mg of mifepristone presented a significantly higher mean value in relation to the placebo (p=0.04). At 72 hours, cervical length showed a significant difference (p<0.01) in both mifepristone groups compared to the placebo group. Also, at 72 hours a significant increase in the mean duration of contractions was demonstrated in the 100 mg mifepristone group.

Conclusions: There was a significant increase in Bishop's score for the 200 mg mifepristone group probably due to a significant increase in contractions at 24 hours. No differences were observed between groups in adverse events.


Keywords


Cervical ripening, Labor induction, Mifepristone

Full Text:

PDF

References


Mahajan DK, London SN. Mifepristone (RU486): a review. Fertil Steril. 1997;68(6):967-76.

Frydman R, Lelaidier C, Mleux C, Fernandez H, Vial M, Bourget P. Labor induction in women at term with mifepristone (RU 486): a double-blind, randomized, placebo-controlled study. Obstet Gynecol. 1992;80(6):972-5.

Newhall EP, Winikoff B. Abortion with mifepristone and misoprostol: regimens, efficacy, acceptability and future directions. Am J Obstet Gynecol. 2000;183(2):44-53.

Tristan M, Orozco LJ, Steed A, Morera A, Stone P. Mifepristone for uterine fibroids. Cochrane Database Systematic Rev. 2012;8:CD007687.

Fu J, Song H, Zhou M, Zhu H, Wang Y, Chen H, Huang W. Progesterone receptor modulators for endometriosis. Cochrane Database Systematic Reviews. 2017;7:CD009881.

Berkane N, Verstraete L, Uzan S, Boog G, Maria B. Use of mifepristone to ripen the cervix and induce labor in term pregnancies. Am J Obstet Gynecol. 2005;192(1):114-20.

Clark K, Ji H, Feltovich H, Janowski J, Carroll C, Chien EK. Mifepristone-induced cervical ripening: structural, biomechanical, and molecular events. Am J Obstet Gynecol. 2006;194(5):1391-8.

Elliott CL, Brennand JE, Calder AA. The effects of mifepristone on cervical ripening and labor induction in primigravidae. Obstet Gynecol. 1998;92(5):804-9.

Fassett MJ, Wing DA. Uterine activity after oral mifepristone administration in human pregnancies beyond 41 weeks' gestation. Gynecol Obstet Invest. 2008;65(2):112-5.

Fathima S, Nayak SR, Rao B, Praveena G, Shameem VPA. Mifepristone in the induction of labour at term. Int J Pharm Biomed Res. 2013;4(3):164-6.

Frydman R, Lelaidier C, Mleux C, Fernandez H, Vial M, Bourget P. Labor induction in women at term with mifepristone (RU 486): a double-blind, randomized, placebo-controlled study. Obstet Gynecol. 1992;80(6):972-5.

Wing DA, Fassett MJ, Mishell DR. Mifepristone for preinduction cervical ripening beyond 41 weeks' gestation: a randomized controlled trial. Obstet Gynecol. 2000;96(4):543-8.

Wing DA, Guberman C, Fassett M. A randomized comparison of oral mifepristone to intravenous oxytocin for labor induction in women with prelabor rupture of membranes beyond 36 weeks' gestation. Am J Obstet Gynecol. 2005;192(2):445-51.

Hapangama D, Neilson JP. Mifepristone for induction of labour. Cochrane Database Systematic Rev. 2009;3:CD002865.

Baev OR, Rumyantseva VP, Tysyachnyu OV, Kozlova OA, Sukhikh GT. Outcomes of mifepristone usage for cervical ripening and induction of labour in full-term pregnancy. Randomized controlled trial. Eur J Obstet Gynecol Reprod Biol. 2017;217:144-9.

Wing DA, Fassett MJ, Mishell DR. Mifepristone for preinduction cervical ripening beyond 41 weeks' gestation: a randomized controlled trial. Obstet Gynecol. 2000;96(4):543-8.

Berkane N, Verstraete L, Uzan S, Boog G, Maria B. Use of mifepristone to ripen the cervix and induce labor in term pregnancies. Am J Obstet Gynecol. 2005;192(1):114-20.