A comparison of cervical ripening modalities among overweight and obese nulliparous gravidas.

Objective: To determine if differences exist among nulliparous overweight and obese gravidas undergoing cervical ripening employing three different agents (dinoprostone, misoprostol, or cervical catheter). Methods: A retrospective cohort study of nulliparous overweight and obese women who underwent induction of labor at two south-central Pennsylvania hospitals between January 2014 and December 2017. Nulliparous gravidas, ≥37 weeks' gestational age, with singleton pregnancies in the vertex presentation, were included in the study. We employed the following definitions: (1) overweight: BMI 25.0-29.9 kg/m2 ; (2) class I obesity: BMI 30.0-34.9 kg/m2 ; (3) class II obesity: BMI 35.0-39.9 kg/m2 ; and (4) class III obesity: BMI >40.0 kg/m2 . The primary outcome measure was the mean difference in induction-to-birth time. A subanalysis was performed to assess the effect of BMI on the primary outcome. Secondary outcome measures included mode of delivery, induction-to-second-stage-of-labor time, estimated blood loss, neonatal feeding type, neonatal Apgar scores, and neonatal admission to triage or intensive care unit (ICU) after delivery. A priori power calculation estimated that 156 patients would be needed using the medium effective size. Data analysis was performed using ANOVA for continuous variables and chi-square tests for categorical variables. Results: Among 192 nulliparous overweight and obese gravidas, 70 received dinoprostone, 72 were given misoprostol, and 50 had cervical ripening with cervical catheters. There were no significant differences in mean induction to birth times among overweight and obese women when comparing the three cervical ripening agents (dinoprostone 24.5 ± 15.2 versus misoprostol 28.7 ± 12.3 and catheters 25.1 ± 12.9 hours), ( p  = .145, 95% CI -8.7 to 0.2 and -5.5 to 4.3, respectively). Overweight nulliparous women had shorter mean induction to birth time (22.9 ± 11.4 versus 29.2 ± 15.8 hours) as compared to class II obese women, ( p  = .037, 95% CI -12.0 to -0.38). When overweight women were compared to class III obese women, shorter mean induction to birth time (22.9 ± 11.4 versus 30.9 ± 13.9 hours) was also found, ( p  = .005, 95% CI -13.4 to -2.4). Conclusion: Among nulliparous overweight and obese gravidas, neither dinoprostone, misoprostol, or cervical catheter significantly impacted the induction to birth time. There was a longer induction to birth time for class II and class III obese women when compared to overweight women. Additional studies are warranted to improve cervical ripening in nulliparous overweight and obese women.