Objective: To determine the optimal method for cervical ripening in women presenting with decreased fetal movements at term. We hypothesized that women who undergo induction of labor for decreased fetal movements represent a higher risk group, and will benefit from mechanical intervention with cervical ripening balloon rather than with pharmacological prostaglandin E2 vaginal insert.
Study design: Retrospective cohort study from January 2014 and January 2019. We recommended induction of labor to every woman ≥39 weeks' gestation with complaints of persistent decreased fetal movements. We excluded women with major fetal anomalies, Bishop score of ≥6 on admission, and cases with contraindications to prostaglandins. Women were allocated into one of two groups based on the cervical ripening agent used. In group 1 we introduced the prostaglandin E2 vaginal insert (10 mg dinoprostone in a timed-release formulation). In group 2 we placed the mechanical cervical ripening balloon. The primary outcome of the study, analyzed separately to nulliparous and multiparous women, was the rate of cesarean delivery in each of the groups.
Results: During the 5-years study, 294 women were included in the final analysis, of which 201 were in the prostaglandin E2 vaginal insert group and 93 were in the cervical ripening balloon group. The rate of cesarean delivery was comparable between the groups (nulliparous: 20.8%, 16/77 versus 21.3%, 10/47. multiparous: 16.9%, 21/124 versus 7%, 3/46, respectively). Other maternal and neonatal secondary outcomes, including the induction-to-delivery time (nulliparous: 32.5 ± 25.3 h versus 26.5 ± 12.2 h. multiparous: 24.6 ± 17.2 h versus 21.25 ± 12.3 h, respectively), were also not different between the two induction methods used. A longer induction-to-delivery time was observed in nulliparous women who had repeat prostaglandin E2 vaginal insert compared with the cervical ripening balloon group (74.6 ± 27.3 h versus 26.5 ± 12.2 h, p < .01).
Conclusion: Both pharmacological and mechanical methods can safely and efficiently be used for cervical ripening in women presenting with decreased fetal movements at term. With repeat prostaglandin E2 use, nulliparous women may experience a prolong labor compared with the cervical ripening balloon group, but maternal or fetal safety are not compromised.
Keywords: Decreased fetal movements; cervical ripening balloon; induction of labor; pregnancy; prostaglandin E2 vaginal insert.