935: Can cerebroplacental ratios predict perinatal and delivery outcomes for viable fetuses?

Abstract

To evaluate the relationship between fetal ultrasound assessments and perinatal and delivery outcomes in singleton term pregnancies. A retrospective cohort study of singleton deliveries ≥ 24 weeks’ gestation was conducted at a community hospital between January 2016 and January 2018. The fetal cerebroplacental ratio (CPR) is the ratio of the fetal middle cerebral artery (MCA) pulsatility index (PI) to umbilical artery (UA) PI. CPR is gaining momentum to be a proxy for suboptimal fetal growth as it quantifies suboptimal placental function and subsequent fetal circulatory adaptations. We hypothesize the use of CPR as a generalized marker and potential screening tool as it looks as placental resistance and fetal physiologic response to reach growth potential for Small for Gestational Age (SGA) fetuses and Appropriate for Gestational Age (AGA) fetuses. The UA PI, MCA PI, and CPR were compared to maternal BMI, fetal weight at birth, delivery outcomes, and APGAR scores. Logistic regression analysis was performed to identify, and adjust for, potential confounders using SAS version 9.4 with a p < 0.05 considered as significant. The study cohort included 1732 singleton pregnancies. CPR had a linear association with fetal weight and gestational age (p < 0.0001). The average CPR ratio of spontaneous vaginal deliveries was higher than of caesarean-sections (C-sections) (p= 0.0193). The average UA PI of spontaneous vaginal deliveries was lower than of C-sections (p= 0.0150). The CPR had a weak positive and UA PI ratio had a weak negative correlation with APGAR score at 1 and 5 minutes. CPR and UA PI had no significant association with maternal BMI (p= 0.2330). Our study shows that lower fetal CPR is associated with higher C-section rates in both SGA and AGA fetuses. Since low CPR is directly correlated with an elevated UA PI Doppler, this surveillance may be independently associated with delivery outcomes. These fetal ultrasound assessments may be valuable in predicting delivery outcomes of pregnancies at risk of operative deliveries, potential placental hypoxemia and cerebral redistribution affecting long-term neurodevelopmental disability.