Umbilicocerebral Ratio Versus Cerebroplacental Ratio in Predicting Perinatal Outcomes in Pregnancies with Early and Late Onset Fetal Growth Restriction: A Retrospective Comparative Study

Abstract

Objectives: To compare the predictive accuracy of umbilico-cerebral ratio (UCR) and cerebro-placental ratio (CPR) for adverse perinatal outcomes in pregnancies complicated by early and late onset fetal growth restriction (FGR).

Material and Methods: A retrospective single-centre study was conducted analysing 105 singleton FGR pregnancies (56 early onset, 49 late onset) between April 2023 and April 2024. Adverse outcomes included caesarean section, premature birth, low birth weight, NICU admission, and need for resuscitation. Receiver operating characteristic (ROC) curves, correlation analyses, and logistic regression were performed.

Results: UCR demonstrated superior predictive performance compared to CPR for multiple adverse outcomes in the total FGR cohort. For cesarean section prediction, UCR showed an area under the curve (AUC) of 0.755 versus CPR's 0.573 (p=0.0001). UCR was significantly associated with reduced risk of caesarean section (OR 0.351, 95% CI 0.174-0.709, p=0.003) and NICU admission (OR 0.275, 95% CI 0.123-0.618, p=0.002), while being associated with increased risk of low birth weight (OR 1.93, 95% CI 1.136-3.279, p=0.015). Early onset FGR pregnancies had significantly higher rates of cesarean section (94.64% vs 75.51%, p=0.01) and NICU admission (41.07% vs 12.24%, p=0.001) compared to late onset FGR.

Conclusions: UCR demonstrates superior predictive accuracy compared to CPR for adverse perinatal outcomes in FGR pregnancies, particularly for cesarean section and NICU admission. The inverted ratio may provide clinicians with a more sensitive tool for risk stratification and management decisions in FGR pregnancies.