Mode of delivery and necrotizing enterocolitis in very preterm very-low-birth-weight infants.

To investigate the association between delivery mode and necrotizing enterocolitis (NEC) in very preterm (24-31 weeks' gestational age (GA)) very-low-birth-weight (VLBW) (≤1500 g) infants. Population-based observational study using univariate and multivariable logistic regression analyses. The Israel National VLBW infant database 1995-2015. 20,223 VLBW infants, 11,832 singletons and 8391 multiples. The association of NEC occurrence to delivery by cesarean section (CS) in singletons and multiples VLBW very preterm infants. NEC occurred in 7.6% of singletons and 6.4% of multiples. 71.5% were delivered by CS (64.7% of singletons, 80.9% of multiples). CS delivery was not significantly associated with NEC stages 2-3 in singletons; but multiple births CS were associated with significantly higher odds for NEC (OR 1.31, 95% CI 1.01-1.69). Odds for NEC were greater with lower GA, small for GA (SGA) and patent ductus arteriosus (PDA) in both singletons and multiples, and lower in multiples with antenatal corticosteroids. We demonstrated association between deliveries by CS and increased risk for NEC only in multiple pregnancies.