Introduction: Given the pharmacological change taking place in Spanish delivery
rooms, we designed this study to compare the effectiveness and safety of
misoprostol (25 mcg/4h) to 10 mg dinoprostone in its slow-releasing vaginalinsert
form to induce at-term labor. Methods: In a prospective cohort study
(2013-2015), 401 at-term pregnant women referred for induction (Bishop
score ≤ 6), who gave birth at the Rey Juan Carlos Hospital in Móstoles (Madrid,
Spain), of whom 241 participants were induced with misoprostol and
160 with dinoprostone. Patients were recruited by non-probabilistic sampling
of consecutive cases as the inductions in the Obstetrics Block during the study
period were indicated. Results: The cesarean section rate was 14% for the misoprostol
group and 19% for the dinoprostone group [RR = 1.38 (95%CI: 0.89
- 2.13), p = 0.145]. No differences were found in the vaginal birth rate in <24 h
from starting induction [44% vs. 53%, RR = 1.08 (0.90 - 1.29), p = 0.401], nor
in the vaginal birth rate in <12 h, requiring oxytocin or meconium fluid, or for
maternal-neonatal complications deriving from the method employed. The
percentage of cesarean sections due to failed induction was lower in the misoprostol
group (15% vs. 39%, p = 0.028). The time between induction and giving
birth was shorter for the dinoprostone group (20 h vs. 23.4 h, p = 0.018).
Conclusion: Inducing delivery by low-dose misoprostol offers similar effectiveness
and safety to induction by dinoprostone in its slow-releasing vaginal-insert form. However, our sample is limited, and few studies are available
on the subject. Further analyses to draw solid conclusions are required.