Fetal Doppler to predict cesarean delivery for non-reassuring fetal status in the severe small-for-gestational-age fetuses of late preterm and term

OBJECTIVE: To evaluate the significance of fetal Doppler parameters in predicting adverse neonatal outcomes and the risk of cesarean delivery due to non-reassuring fetal status, in severe small for gestational age (SGA) fetuses of late preterm and term gestation. METHODS: Fetal brain and umbilical artery (UmA) Doppler parameters of cerebroplacental ratio (CPR) and UmA pulsatility index (PI) were evaluated in a cohort of 184 SGA fetuses between 34 and 41 weeks gestational age, who were less than the 5th percentile. The risks of neonatal morbidities and cesarean delivery due to non-reassuring fetal status were analyzed. RESULTS: Univariate analysis revealed that abnormal CPR was significantly associated with cesarean delivery due to non-reassuring fetal status (P=0.018), but not with neonatal morbidities. However, abnormal CPR did not increase the risk of cesarean delivery due to non-reassuring fetal status in multivariate logistic regression analysis. Abnormal CPR with abnormal PI of UmA was associated with low Apgar score at 1 minute (P=0.048), mechanical ventilation (P=0.013) and cesarean delivery due to non-reassuring fetal status (P<0.001), in univariate analysis. It increased risk of cesarean delivery for non-reassuring fetal status (adjusted odds ratio, 7.0; 95% confidence interval, 1.2–41.3; P=0.033), but did not increase risk of low Apgar score or mechanical ventilation in multivariate logistic regression analysis. CONCLUSION: Abnormal CPR with abnormal PI of UmA increases the risk of cesarean delivery for non-reassuring fetal status, in severe SGA fetuses of late preterm and term. Monitoring of CPR and PI of UmA can help guide management including maternal hospitalization and fetal monitoring.