Feed intolerance in preterm neonates with antenatal reverse end diastolic flow (REDF) in umbilical artery: a retrospective cohort study

Background: Feed intolerance is common in growth-restricted infants with antenatal AREDF (absent or reverse end-diastolic flow) and presumed to be more severe in those with reverse end diastolic flow (REDF). Natural history of feeding in REDF is rarely reported in the literature. Aims and objectives: To determine the incidence of feed intolerance and necrotizing enterocolitis (NEC) in neonates with antenatal REDF. Design: Preterm inborn neonates with gestation <37 weeks with antenatal REDF diagnosed between January 2015 and September 2017 were included in this retrospective cohort study. The primary outcome was the proportion of neonates having feed intolerance and NEC till discharge or death or transfer to other hospitals and time to achieve full enteral feeding (150 ml/kg/day). Results: Out of total 67 born with antenatal REDF, 8 were transferred out within 48 hours, 8 records not available and 4 excluded due to major malformations. The mean (SD) gestation and birth weight of the remaining 48 neonates were 32 (2) weeks and 1096 (291) g. The median (IQR) age of initiation of feeds was 30 (24-37) hours. Feeds were advanced by median (range) 20 (10-20) ml/kg/day in which 22 babies (45%) had at least 1 episode of feed intolerance at a median (IQR) age of 79 (40-120) hours requiring nil per oral for next 48 (18-96) hours. Full feeds were reached by median age (IQR) of nine (8-12) days. Only 3 neonates (6%) had NEC stage 2 or above as per Bell's staging. Conclusions: Feed intolerance is common in neonates with REDF though the risk of NEC is not high.What is known on this subject? Neonates with antenatal AREDF are at increased risk of feed intolerance and necrotizing enterocolitis. Early introduction of enteral feeds in neonates with AREDF with appropriate monitoring is safe without increased risk of necrotizing enterocolitis. AEDF which progresses to REDF is associated with increased morbidity. What does this study add? Early enteral feeding as early as 24 hours can be initiated in REDF if there are no abdominal symptoms and signs. Feed intolerance is high in REDF cases. The risk of NEC is not higher than what is seen in AEDF cases.