Cerebroplacental Ratio as a Predictor of Perinatal Outcome in Hypertensive Disorders of Pregnancy and Its Comparison With Its Constituent Doppler Indices

Abstract

Objective Doppler velocimetry is an established method of antepartum fetal surveillance in pre-eclampsia. Cerebroplacental ratio detects the centralization of fetal blood flow and the insufficiency in placental circulation. It is postulated to be a better marker of perinatal outcome than either vessel Doppler alone. The current study aims to assess the cerebroplacental ratio as a predictor of adverse perinatal outcomes and compare it to the systolic/diastolic (S/D) ratio of umbilical artery (UA) and middle cerebral artery (MCA) in hypertensive disorders of pregnancy. Material and methods The present prospective observational cohort study included 100 patients with hypertensive disorders of pregnancies between 32 and 37 weeks. Ultrasound with Doppler was done and the following parameters were assessed: fetal biometry, amniotic fluid index, umbilical artery pulsatility index, middle cerebral artery pulsatility index, S/D ratio of umbilical artery, S/D ratio of middle cerebral artery, and cerebroplacental ratio. Sensitivity, specificity, positive and negative predictive values were calculated for the cerebroplacental ratio and S/D ratios of umbilical and middle cerebral arteries. McNemar’s test was used for the comparison of sensitivity and specificity. Results Thirty-two patients had an abnormal cerebroplacental ratio. Adverse perinatal outcomes such as a cesarean section for fetal distress, small for gestational age, APGAR < 7 at 1 and 5 minutes, NICU admission, and perinatal mortality were more in the group with abnormal cerebraplacental ratio and the difference was statistically significant. Conclusion The cerebroplacental ratio is a more reliable predictor of adverse perinatal outcomes and should be routinely calculated during obstetrical Doppler for antepartum fetal surveillance in case of hypertensive disorders of pregnancy. It suggested that the cerebroplacental ratio may be calibrated in the software of the Doppler ultrasonography machine for routine use in high-risk pregnancies.