245: Cerebroplacental ratio (CPR) compared with umbilical artery (UA) Doppler alone for the prediction of neonatal small for gestational age (SGA) and short term adverse outcomes

Abstract

Recent studies suggest that the CPR improves identification of pregnancies at risk for adverse neonatal outcomes. We aimed to compare CPR to UA Doppler in the prediction of neonatal SGA and short term adverse neonatal outcome in a high-risk population. We conducted a prospective study on women referred for fetal growth ultrasounds between 26 and 36 weeks of gestation and with an EFW < 20th percentile by Hadlock standard. UA and middle cerebral artery (MCA) Doppler assessments were performed. Abnormal UA Doppler was defined as: pulsatility index (PI) above the 95th percentile and absent or reverse end diastolic flow. The CPR, calculated as a ratio of the MCA PI to the UA PI, was defined as low if < 1.08. We calculated sensitivity and specificity of the two Doppler parameters to predict neonatal SGA (defined as birthweight < 10th percentile by using Alexander curves); and early adverse neonatal outcomes including: umbilical cord arterial pH < 7.10, APGARS at 5 minutes < 7, NICU admission, respiratory distress syndrome (RDS), hypoglycemia or a composite including any of these secondary outcomes, neonatal seizure, grade III or IV intraventricular hemorrhage (IVH) or death. Of 209 women meeting inclusion criteria, 94 (45%) had SGA and 68 (32.5%) had a composite adverse outcome. There was a significant association between abnormal UA Doppler (RR 2.9, 95%CI 1.1, 1.80), but not low CPR (RR 1.2, 95% CI 0.30, 4.6), and SGA. The overall predictive ability for SGA was significantly higher for abnormal UA (area under the ROC curve (AUC) 0.54 vs 0.50, p=0.04). Abnormal UA Doppler had better sensitivity for predicting SGA and adverse neonatal outcomes (Table), with comparable specificity to low CPR. The AUCs for predicting a composite adverse neonatal outcome were: 0.57, 95% CI 0.52-0.62 for abnormal UA Doppler; and 0.53, 95% CI 0.49-0.56 for low CPR (p=0.07) [Figure]. CPR did not improve our ability to predict neonatal SGA or other short term adverse outcomes. Therefore, it should not be used in clinical practice until further studies demonstrate its reliability.View Large Image Figure ViewerDownload Hi-res image Download (PPT)