Predictive Value of Doppler Cerebroplacental Ratio for Adverse Perinatal Outcomes in Postdate Pregnancies in Northwestern Nigeria

Background: Postdate pregnancy is a very common obstetric condition, increasing the risk of perinatal morbidity and mortality from uteroplacental insufficiency. Aim: To determine the predictive values of Doppler cerebroplacental ratio (CPR), that is, the ratio between middle cerebral artery (MCA) and UA pulsatility indices (UA PI), and other potential velocimetric predictors of adverse perinatal outcomes in women with postdated pregnancies. Patients and Methods: A prospective cohort study was conducted on consenting 212 low-risk pregnant women beyond 40 weeks' gestational age. The pulsatility indices of MCA, UA, and CPR as well as non-stress tests (NST) and amniotic fluid index (AFI) were measured and recorded. The women were divided into two groups based on the presence or absence of adverse perinatal outcome defined as: meconium stained liquor, meconium aspiration syndrome, perinatal asphyxia, cesarean section for suspected fetal distress, and perinatal death. Results: Of the 200 women whose data were available for analysis, 40 (20%) of them had adverse perinatal outcome and 160 (80%) had normal perinatal outcome. The CPR showed statistically significant difference in predicting adverse perinatal outcome (P < 0.001). CPR had a better predictive value than UA-PI and outperformed MCA-PI and NST for adverse perinatal outcomes. The sensitivity, specificity, negative predictive value (NPV), and accuracy of prediction of adverse perinatal outcomes by CPR were 90%, 81.25%, 97.01%, and 83%, respectively. Conclusion: The Doppler CPR shows the highest diagnostic accuracy in prediction of adverse perinatal outcome in pregnant women after 40 weeks' gestation than UA PI and velocimetric indices when used as stand-alone test.