Prognostic Factors of Successful Cervical Ripening and Labor Induction in Late-Onset Fetal Growth Restriction.

OBJECTIVE: The aim of this work was to identify independent risk factors influencing the achievement of vaginal delivery among women undergoing labor induction for late-onset fetal growth restriction (FGR). METHODS: This was a retrospective cohort study of 201 singleton pregnancies with late-onset FGR (diagnosed >32 + 0 weeks) that required labor induction with cervical ripening from 37 + 0 weeks, either with dinoprostone (from 2014 to 2015) or Foley balloon (from 2016 to 2018). Independent factors for successful vaginal delivery were identified. A prediction model of vaginal delivery with the identified factors was made using logistic regression and bootstrapping with 1,000 re-samples performed for bias correction. RESULTS: Perinatal results were more favorable in the vaginal delivery group, with significantly lower neonatal admission rates (4.0 vs. 13.7%) and lower composite neonatal morbidity (4.0 vs. 15.7%). The labor induction method (Foley balloon), higher cerebro-placental ratio, lower pre-gestational BMI, and absence of pre-eclampsia were identified as independent factors associated to vaginal delivery. The area under the curve of the model was of 0.75 (95% CI 0.70-0.79). CONCLUSIONS: The use of a Foley balloon is the only modifiable risk factor to improve the chances of vaginal delivery when attempting induction of labor in singleton pregnancies with late-onset FGR.