Safety of misoprostol as a cervical ripening agent in vaginal birth after cesarean section

Abstract In women who underwent vaginal birth after cesarean section (VBAC), we assessed the risk of uterine rupture in those who received misoprostol and oxytocin (M+O) compared with that in two other groups—VBAC patients who had spontaneous labor (SL) and those who received oxytocin alone (OA). From 1996 to 1999, we compared risks for fetal and maternal complications, including uterine rupture, in M+O patients versus SL patients and in M+O patients versus OA patients. Other complications included abnormal heart rate pattern in labor, meconium passage, intrapartum infection, uterine rupture, and failure of VBAC. Of 382 VBAC patients studied, we had 100 patients in the M+O group, 115 in SL, and 167 in OA. There were no cases of uterine rupture in any of the three groups. Comparing M+O and SL patients, M+O patients were significantly less likely to have meconium ( P = .002) and less likely to have an abnormal heart rate pattern ( P = .02) than SL patients. Between M+O and OA patients, no statistically significant differences were identified in all outcomes measured. There were no cases of uterine rupture in any of the three groups. Three cases of uterine dehiscence were identified, but none of them received misoprostol. Success for vaginal delivery was statistically the same in all three groups (79% in M+O, 77% for SL, and 84% for OA). In conclusion, the use of misoprostol was not associated with an increased risk of abnormal fetal heart rate, maternal infection, or uterine rupture. In our series, misoprostol in VBAC patients was a relatively safe method for cervical ripening and as successful as spontaneous labor or oxytocin in vaginal delivery.