Dinoprostone Compared With Misoprostol for Cervical Ripening for Induction of Labor at Term

Abstract

H.L. is a 25‐year‐old woman, gravida 2 para 1‐0‐0‐0 admitted to the birth unit at 38 and 6/7 weeks' gestation for induction of labor because of an obstetric history of a previous intrauterine fetal demise (IUFD) at term. The previous pregnancy occurred 5 years before this pregnancy, and the etiology of the IUFD was not determined. The current pregnancy was uncomplicated. Maternal serum alpha‐fetoprotein and gestational diabetes screening were normal. Serial sonograms and the biweekly nonstress tests (NST) that were first performed at 32 weeks' gestation showed no abnormalities. The cervical examination on admission was 1 cm dilated, 50% effaced, medium consistency and posterior, −3 station, vertex presentation, equivalent to a Bishop score of 3, with membranes intact. The NST conducted on admission was reactive and she had no significant uterine activity. After informed consent and consultation between the midwife and attending obstetrician, the plan to administer 25 mcg of misoprostol (Cytotec) per vagina, every 4 hours, for up to 6 doses, was initiated. H.L. began feeling mild contractions after receiving her third dose of misoprostol; however, her cervical examination remained unchanged. A routine change in the inpatient obstetric providers resulted in a change from continued vaginal misoprostol to use of vaginal 10 mg dinoprostone (Cervidil) for cervical ripening. This change in medical induction agents was based on the belief and experience of the incoming midwife that dinoprostone is a better ripening agent, and the fact that there had been no cervical change after 3 doses of misoprostol. Two hours after insertion of the dinoprostone, H.L. had a period of tachysystole. The dinoprostone was removed from the vagina, oxygen via face mask was started, and 0.25 mg of terbutaline was given subcutaneously. After 6 hours of rest and observation, the cervical examination was 2 cm dilated, 70% effaced, −2 station. An oxytocin infusion was started at 1 milliunit per minute, and was increased to a maximum of 2 milliunits per minute with adequate uterine contractions. After 2 more hours, H.L.'s cervical examination was 2 to 3 cm dilated, 70% effaced, −1 station, with bulging membranes. Membranes were artificially ruptured at this time, and the fluid was noted to be clear. After an hour and a half of intense, frequent contractions, H.L. requested an epidural. A cervical examination revealed labor had progressed to 6 to 7 cm, 100% effaced, and 0 station. Twenty minutes later—coincidentally, the same time as the arrival of the anesthesiologist—H.L. sat up and began spontaneous pushing efforts. She was examined and found to be fully dilated. Following a 6‐minute second stage of labor, a 7 lb, 2 oz male was born spontaneously and without difficulty, with a loose nuchal cord, and Apgar scores of 9 and 9, at 1 and 5 minutes, respectively. The placenta was delivered spontaneously and grossly intact after a 7‐minute third stage of labor. There were no lacerations or excessive uterine bleeding. The postpartum and neonatal periods progressed well.