Objective: To compare the accuracies of several sonographic parameters for the prediction of adverse perinatal outcome (APO) prior to delivery.
Methods: This was a prospective study of fetuses attending the day hospital unit of a tertiary referral hospital that were scanned at 34-41 weeks and gave birth within 24 h of examination. APO was defined as a composite of abnormal intrapartum fetal heart rate or intrapartum fetal scalp pH < 7.20 requiring urgent cesarean section, neonatal umbilical cord pH < 7.10, 5' Apgar score <7 and postpartum admission to neonatal or pediatric intensive care units. The accuracies of the middle cerebral, vertebral and umbilical arteries pulsatility index multiples of the median (MoM), the cerebroplacental and vertebroplacental ratios MoM and the EFW in centiles for the prediction of APO was evaluated by means of ROC curves and logistic regression analysis.
Results: A total of 2140 fetuses were prospectively scanned, however only 182 entered into spontaneous or induced labor and were delivered within 24 h of examination. In this group, MCA PI MoM was the best predictor of APO (AUC = 0.76, 95% CI 0.66-0.85, p < .0001) followed by the CPR MoM (AUC = 0.73, 95% CI 0.63-0.84, p < .0001) and the VPR MoM (AUC = 0.71, 95% CI 0.61-0.81, p < .001). Logistic regression analysis indicated that MCA PI MoM was the only independent determinant for the prediction of APO.
Conclusion: In a high-risk population of third-trimester fetuses delivering within 24 h of examination, the outcome may be moderately anticipated just with the information provided by the cerebral flow.
Keywords: Fetal Doppler; adverse perinatal outcome; cerebroplacental ratio; estimated fetal weight; middle cerebral artery.