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

Objective: 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. Design: Population-based observational study using univariate and multivariable logistic regression analyses. Setting: The Israel National VLBW infant database 1995-2015. Patients: 20,223 VLBW infants, 11,832 singletons and 8391 multiples. Main outcome measures: The association of NEC occurrence to delivery by cesarean section (CS) in singletons and multiples VLBW very preterm infants. Results: 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. Conclusions: We demonstrated association between deliveries by CS and increased risk for NEC only in multiple pregnancies.