Fetal cerebro-placental ratio and adverse perinatal outcome: Systematic review and meta-analysis of the association and diagnostic performance

Objective: The objective of this meta-analysis is to assess the value of fetal cerebro-placental Doppler ratio (CPR) in predicting adverse perinatal outcome in pregnancies with fetal growth restriction (FGR). Methods: Three databases were used: MEDLINE, EMBASE (with online Ovid interface) and SCOPUS and studies from inception to April 2015 were included. Studies that reported perinatal outcomes of fetuses at risk of FGR or sonographically diagnosed FGR that were evaluated with CPR were considered eligible. Perinatal outcomes include cesarean section (CS) for fetal distress, APGAR scores at 5 min, neonatal complications and admission to neonatal intensive care unit (NICU). Pooled data were expressed as odds ratio (OR) and confidence intervals (CI), and the summary receiver operating characteristic (SROC) curve was used to illustrate the diagnostic accuracy of CPR. Results: Seven studies were eligible (1428 fetuses). Fetuses with abnormal CPR were at higher risk of CS for fetal distress (OR=4.49, 95% CI [1.63, 12.42]), lower APGAR scores (OR=4.01, 95% CI [2.65, 6.08]), admission to NICU (OR=9.65, 95% CI [3.02, 30.85]), and neonatal complications (OR=11.00, 95% [3.64, 15.37]) than fetuses who had normal CPR. These risks were higher among studies that included fetuses diagnosed with FGR than fetuses at risk of FGR. Abnormal CPR had higher diagnostic accuracy for adverse perinatal outcomes among "sonographically diagnosed FGR" studies than "at risk of FGR" studies. Conclusion: Abnormal CPR is associated with substantial risk of adverse perinatal outcomes. The test seems to be particularly useful for follow up of fetuses with sonographically diagnosed FGR.