Comparison of Cerebroplacental Ratio, Intergrowth-21st Standards, Customized Growth, and Local Population References for the Prediction of Fetal Compromise: Which Is the Best Approach?

OBJECTIVE: The aim of this work was to compare the accuracy of the cerebroplacental ratio (CPR), Intergrowth 21st standards (IG21), customized growth (CG), and local population references (LPR) in the prediction of intrapartum fetal compromise (IFC).

METHODS: This was a prospective study of 714 fetuses that underwent an ultrasound examination at 34-41 weeks and were delivered within a 2-week interval. The CPR was converted into multiples of the median and the estimated fetal weight (EFW) transformed into CG, IG21, and LPR centiles. IFC was defined as a composite of abnormal cardiotocogram, intrapartum pH requiring cesarean section, 5-min Apgar score, and admission to pediatric care units. The accuracies of the CPR and the EFW centiles for the prediction of IFC were evaluated alone and in combination with other gestational characteristics using univariate and multivariate analysis.

RESULTS: Individually, the CPR was the parameter that best predicted the existence of IFC (AUC = 0.66). The multivariate analysis showed that the best prediction was again achieved with the CPR, alone or in combination with any of the EFW centiles (AUC = 0.74). No significant differences were seen between the different centile methods.

CONCLUSION: The best prediction of IFC is obtained with CPR. Evaluation of CPR should be encouraged in term and late-preterm fetuses.