The role of different Doppler parameters in predicting adverse neonatal outcomes in fetuses with late-onset fetal growth restriction

Objective: The aim of this study is to clarify the role of different Doppler parameters such as umbilicocerebral ratio (UCR), cerebroplacentouterine ratio (CPUR), aortic isthmus, renal artery, and umbilical vein flow Doppler in predicting adverse neonatal outcomes in fetuses with late -onset fetal growth restriction. Materials and Methods: The study included all patients diagnosed with fetal growth restriction at 32-39 weeks' gestation between 01/02/2020 and 01/02/2022 and treated at the Department of Obstetrics and Gynecology, Inonu University School of Medicine. Results: Patients included in the study had a median gestational week at delivery of 37 (minimum 33+0-maximum 39+0), median CPR of 1.42 (minimum-maximum 0.43-3.57), and median UCR of 0.7 (minimum-maximum 0.28-2.3). Receiver operating characteristic analysis was performed to determine the performance of the measured obstetric Doppler parameters in predicting the development of adverse neonatal outcomes. Umbilical venous blood flow showed the best performance in predicting adverse neonatal outcomes [area under the curve 0.952, 95% confidence interval (CI) 0.902-0.981, p<0.001]. Multivariate logistic regression analysis showed that fetuses with abnormal CPUR had a 4.5-fold (95% CI 0.084-0.583, p=0.02) increased risk of adverse neonatal outcome, whereas fetuses with abnormal umbilical venous flow had a 1.07-fold (95% CI 0.903-0.968, p<0.001) increased risk of adverse neonatal outcome. Conclusion: The results of this study demonstrate that the use of UCR, CPUR, umbilical venous flow, and aortic isthmus PI Doppler parameters along with umbilical artery PI and CPR are effective in predicting adverse neonatal outcomes in fetuses with late -onset fetal growth restriction.