Cerebroplacental Ratio as a Predictor of Perinatal Adverse Outcome in Appropriate for Gestational Age (AGA) fetuses

Background The cerebroplacental ratio (CPR) is the ratio of the Doppler pulsatility indices of the Middle Cerebral Artery and the Umbilical Artery. A value less than 1 can be used to screen for pregnancies at high risk of adverse perinatal outcomes. The objective of this study was to determine the accuracy of CPR in predicting adverse outcomes in appropriate for gestational age (AGA) fetuses. Methods This prospective observational study was conducted in the Department of Radiology at a tertiary care hospital in India. It included 144 pregnant women having singleton pregnancies at term. Exclusion criteria was patients with multiple pregnancies, unknown last menstrual period with no dating scan, complicated pregnancies, congenital malformations and chromosomal abnormalities, pregnancies with known fetal growth retardation (FGR), and women with known placental abnormalities. The cerebroplacental ratio was calculated using duplex Doppler ultrasonography. The possible outcomes were Caesarean section or instrumental delivery for fetal distress, NICU admission, APGAR score < 7 at 5 minutes, or a normal outcome. Results A total of one hundred and forty-four singleton pregnancies were included. According to study results, patients with CPR < 1 were more likely to experience adverse outcomes than patients with CPR > 1. Sensitivity was 63.6% and specificity was 92.1%. Conclusion The study results prove that a finding of CPR value < 1 at term is a strong predictor of adverse outcome. However, due to the low sensitivity of CPR, it should be used as an adjunctive method of detecting adverse outcomes, and not an independent measure.