Abstract
To stratify apparently low-risk pregnant women into those who are at risk of adverse perinatal outcomes. Appropriate stratification would allow targeted prenatal and intrapartum management.
This prospective, observational study included normotensive women with appropriately grown, non-anomalous, singleton pregnancies. Participants underwent fortnightly ultrasounds from 36 weeks' gestation and intrapartum and neonatal outcomes were recorded. The association between uterine artery pulsatility index (UtA-PI), the cerebroplacental ratio (CPR) and estimated fetal weight (EFW) were explored along with their screening performance for CS-IFC and CNM.
The final cohort included 429 women. As continuous variables, UtA-PI and the CPR were not correlated (rho = -0.05, p = .33). UtA-PI >95
centile and the CPR <10
centile were predictive of CS-IFC and CNM, with the highest sensitivity achieved by their combination (33.3%, 95% CI 11.6-55.1) for a false positive rate (FPR) of 15.8% (12.3-19.3). For CNM, the highest sensitivity (28.4%, 95% CI 18.6-38.2) and corresponding FPR (17.0%, 95% CI 13.0-20.9) was achieved by combining UtA-PI 95
centile, the CPR 10
centile and EFW 10
centile. EFW was the weakest of the three predictors.
In this population, UtA-PI 95
centile and the CPR 10
centile have modest screening performance for CS-IFC and CNM.