Fetal growth restriction: risk factors for unplanned primary cesarean delivery.

Objective: The purpose of this study was to identify risk factors before or during labor to predict primary cesarean delivery for non-reassuring fetal heart tracing in cases of fetal growth restriction (FGR) undergoing a trial of labor.

Study Design: We reviewed charts of all patients with singleton, non-anomalous fetuses found to have FGR and delivered from January 2008 to December 2012. Characteristics of patients delivered by cesarean were compared to those who had delivered vaginally.

Results: Two hundred and twenty-two patients were delivered with FGR. Fifty-nine patients were excluded due to cesarean delivery prior to labor. Of the remaining 153 patients, 84% delivered vaginally and 16% underwent cesarean delivery. Of the 131 patients who underwent induction, 83% delivered vaginally. Rates of cesarean were higher for primigravity, oligohydramnios and prostaglandin use. However, logistic regression showed that oligohydramnios (odds ratio [OR]: 3.98; CI: 1.35-11.76) and prostaglandin use (OR: 3.67; CI: 1.07-12.60) were significantly associated with cesarean delivery.

Conclusions: The rate of vaginal delivery is high in cases of FGR undergoing a trial of labor. We recommend that these patients undergo a trial of labor. Patients with oligohydramnios and those requiring prostaglandins for cervical ripening should be counseled regarding a significantly higher risk of cesarean delivery.