A comparison of orally administered misoprostol to intravenous oxytocin for labor induction in women with favorable cervical examinations.
OBJECTIVE
The purpose of this study was to compare orally administered misoprostol with intravenous oxytocin infusion for labor induction in women with favorable cervical examinations (defined as a Bishop score of 6 or more).


METHODS
One hundred ninety-eight women with indications for labor induction and favorable cervical examinations were assigned randomly to receive oral misoprostol or oxytocin induction. Misoprostol, 100 mg, was administered every 4 hours up to 6 doses, or intravenous oxytocin was administered by standardized protocol.


RESULTS
One hundred ten (55.6%) women received misoprostol; 88 (44.4%) received intravenous oxytocin. There was no statistically significant difference in the average interval from start of induction to vaginal delivery, being longer in the misoprostol group (789.4 +/- 510.2 minutes) than in the oxytocin group (654.0 +/- 338.2 minutes, P=.19, log-transformed data). Two women had tachysystole develop in each treatment group. More women in the misoprostol group experienced hyperstimulation (7/110, 6.4%) than in the oxytocin group (0/88, P=.02, Fisher exact test). Nine (8.1%) misoprostol-treated women and 8 (9.1%) oxytocin-treated women underwent cesarean deliveries (P=.82). There was a presumed uterine rupture in a misoprostol-treated multipara women. There were no statistically significant differences in neonatal outcomes between the groups.


CONCLUSIONS
Oral misoprostol offers no benefit over intravenous oxytocin for labor induction in women with favorable cervical examinations. It is associated with a higher likelihood of uterine hyperstimulation and may increase the risk of uterine rupture.
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Southern California-Keck School of Medicine, Los Angeles, 90033, USA. dwing@usc.edu
Deborah A
DA
Wing
Michael J
MJ
Fassett
Cristiane
C
Guberman
Susan
S
Tran
Antigone
A
Parrish
Debra
D
Guinn
D000284:Administration, Oral; D020070:Cervical Ripening / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005865:Gestational Age; D006801:Humans; D007262:Infusions, Intravenous; D007751:Labor, Induced / Q000379:methods; D016595:Misoprostol / Q000008:administration & dosage*; D010120:Oxytocics / Q000008:administration & dosage*; D010121:Oxytocin / Q000008:administration & dosage*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011336:Probability; D018570:Risk Assessment; D016896:Treatment Outcome; D014590:Uterine Contraction / Q000187:drug effects
D010120:Oxytocics; D016595:Misoprostol; D010121:Oxytocin