Vaginal Misoprostol for Cervical Ripening at Term: Comparison of Outpatient vs. Inpatient Administration

Abstract

Misoprostol is a prostaglandin E1 analog that is widely used to ripen the cervix. It is relatively inexpensive and reportedly more effective than prostaglandin E2 in promoting vaginal delivery within 24 hours and with less oxytocin. This study evaluated outpatient misoprostol therapy in 177 pregnant women at 38 weeks gestation or later who had an unfavorable cervix (cervix ≤2 cm and station ≥0). All had a reactive nonstress test without regular contractions and no medical or obstetric complications. A single dose of 50 μ was given intravaginally. A control group included 96 women who received misoprostol in the hospital. The 2 groups were similar in maternal age, parity, gestational age, and initial cervical dilation and station, but the inpatient group had medical or obstetric complications that disqualified them from outpatient management. There were no home deliveries in the outpatient group. The outpatient treatment group was more likely to have advanced cervical dilation (4–9 cm) at hospital admission the following morning than the inpatient group (10.2% vs 2.1%; relative risk [RR], 5.0; 95% confidence interval [CI], 1.2–21.5). Most patients in both groups required either no oxytocin or only low doses to augment contractions. The interval from admission to delivery was significantly shorter in women receiving outpatient treatment, averaging 3.1 hours in nulliparas and 5.3 hours in multiparas. No group differences were apparent in contractions occurring every 5 minutes or more often, regular contractions at the time of hospital admission, fetal intolerance of labor, low Apgar scores, or neonatal complications. There were no failed inductions in either the outpatient or inpatient group and no cases of placental abruption or uterine rupture. Spontaneous vaginal delivery was more common in the outpatient group (80.2% vs 63.5%; RR, 1.27; 95% CI, 1.04–1.55), and operative deliveries were less frequent, although not significantly so. Infants in both groups did well. It appears reasonable to administer misoprostol to outpatients—a group that represented approximately two thirds of women with an unfavorable cervix who had labor induced at term. The delay associated with outpatient therapy may allow more time for labor to begin, resulting in more advanced cervical dilation at the time of hospital admission and reduced intervals from admission to vaginal delivery regardless of parity.