Effect of extra-amniotic Foley's catheter and vaginal misoprostol versus vaginal misoprostol alone on cervical ripening and induction of labor in Kenya, a randomized controlled trial

Abstract

Background: The safest, most effective and fastest combined approaches to induction of labor is unknown. In an open-label randomized clinical trial we evaluated the efficacy of combination of extra-amniotic Foley's catheter and vaginal misoprostol compared to vaginal misoprostol alone for cervical ripening and induction of labor on the incidence of failed induction, induction-to-delivery interval and adverse maternal and perinatal outcomes. Methods: Pregnant women at gestational age of 28 weeks or greater admitted at Kenyatta National Hospital, Kenya for induction of labor were enrolled then randomized to either a combination of extra-amniotic Foley's catheter inflated by 30 cm 3 of normal saline and 25 micrograms of vaginal misoprostol or 25 micrograms of vaginal misoprostol alone. Women underwent 6 hourly reviews and additional misoprostol inserted if required. The primary outcome was incidence of failed induction. Secondary outcomes were induction-to-delivery interval and adverse maternal and perinatal outcomes. We conducted an intent-to-treat analysis and compared means or medians using t-test or Wilcoxon rank, proportions using Chi-square or Fishers test as appropriate. Induction-to-delivery interval were compared using the log-rank test. P-values of < 0.05 and 95% confidence intervals that excluded the null were considered statistically significant. Results: Between February and May 2016, we enrolled 180 of 237 pregnant women admitted for induction of labor and randomized them to either a combination of extra-amniotic Foley's catheter and vaginal misoprostol (n = 90) or vaginal misoprostol alone (n = 90). The socio-demographic and obstetric characteristics were similar between the two groups. Failed induction rates were lower but not statistically significant following combined extra-amniotic Foley's catheter and vaginal misoprostol (8.9%) versus vaginal misoprostol alone (11.1%). The mean induction-to-delivery time was 4.8 h shorter in the combined extra-amniotic Foley's catheter and vaginal misoprostol (mean 18.9, standard deviation (SD) 7.2 h) compared to misoprostol only group (mean 14.1, SD 6.9 h) (log-rank test, p < 0.001). Maternal and perinatal complications were similar between the two groups. Conclusions: Extra-amniotic Foley's catheter and vaginal misoprostol for cervical ripening and induction of labor did not significantly lower the incidence of failed induction but safely shortened induction-to-delivery time compared to vaginal misoprostol only.