P25.05: Uterine Doppler, cerebroplacental ratio and fetal growth in the late third trimester: association with adverse outcome

Abstract

To determine the performance of uteroplacental Doppler plus cerebroplacental ratio and fetal growth and its association with adverse perinatal outcome (APO) and birthweight below p3 in pregnancies explored at late third trimester. A retrospective cohort of low risk singleton pregnancies scanned at 37 gestational weeks was reviewed. At inclusion, biometry for estimated fetal weight (EFW) and fetoplacental Doppler evaluation (uterine artery pulsatility index [UtA-PI], cerebroplacental ratio [CPR] normalised by EFW. Estimated fetal weight defining two groups above and below to the 10th centile. APO was defined as the occurrence of composite morbidity including emergent Caesarean section for non-reassuring fetal status, 5-min Apgar score <7 or neonatal acidosis at birth defined by ph venous below 7.1, admission at NICU and stillbirth. A total of 2272 pregnancies were included. Among these, 65.2% were nulliparous and 34.8% were multiparous , 176 cases of Adverse perinatal outcome APO, 20,6%. Using uterine Doppler above p95 th centile as the predictor of adverse outcome we found 30% of cases within the estimated fetal weight below 10 centile and 14.8% in the above 10th. Odds ratio of 2,28 (1,5-3.4). Regarding CPR within the two groups of EFW the odds ratio for adverse outcome was 2.6 (1.8-3.6) in the group of SGA and 1,52 (1.02-2-44) for the AGA group. The model combining efw plus uterine Doppler above p95 and cpr below p5 had an AUC of 0,58 (0,54-0.61) for the prediction of Adverse perinatal outcome with a sensitivity of 20.2% for a false positive of 9,5%. Using the same model including uterine Doppler and CPR according to estimated fetal weight for the prediction of FGR <P3 birthweight the Sensitivity is 16% for a false positive of 3,2%. The combination of uterine Doppler and Cerebroplacental ratio is associated with adverse perinatal outcome, although significant the predictive values are very low. The performance improves in the cases of estimated fetal weight below the 10th centile.