Early feeding tolerance in small for gestational age infants with normal versus abnormal antenatal Doppler characteristics

OBJECTIVES: To determine differences in feeding tolerance amongst preterm small for gestational age (SGA) infants with normal versus abnormal umbilical artery Doppler flow defined as absent or reversed end diastolic flow (AREDF). METHODS: This was a retrospective cohort study of infants<35 weeks gestational age (GA) and birth weight (BW) <10th percentile. Day of initiation of feeds, days to full feeds and CRIB II scores were the primary outcomes. Clinical characteristics were compared between the groups of SGA infants with normal and AREDF. Multivariable regression models were fit to the data to adjust for potential confounders of the association of AREDF and feeding intolerance. RESULTS: 120 infants with normal and 64 infants with AREDF were included. The infants with AREDF were smaller (971g vs. 1183g, p=0.0002), less mature (29.9 wks vs. 31.2 wks, p=0.0009), had higher CRIB II score (7.2 vs. 5.2, p=0.0033), started feeding later (4.1 days vs. 3.3 days, p=0.020) and advanced slower to full feeds (17.7 days vs. 13.7 days, p=0.0017). Necrotizing enterocolitis was similar between the groups (p=0.18). After adjusting for confounders, Doppler flow was no longer a significant predictor of the initiation (p=0.37) and advancement of feeds (p=0.44). CONCLUSIONS: Infants with AREDF are sicker at birth and have more feeding difficulties; after adjusting for BW and GA, Doppler flow was no longer a significant predictor of feeding intolerance.