Neonatal antibiotic exposure and the risk NEC

In this issue of The Journal, Alexander et al report a retrospective case control study performed in a single neonatal intensive care unit (NICU) over a 9 year period, assessing potentially relevant exposures from birth to onset of necrotizing enterocolitis (NEC) in cases and from birth to the same postnatal age in controls. Matching controls-to-cases (2:1), investigators controlled for gestational age, birth weight, and year of NICU admission, and assessed 9 possible NEC associations. In multivariate regression analysis, authors found exposure to antibiotics prior to NEC as statistically significant (adjusted OR 1.10; 95% CI 1.02-1.19) and also showed a “dose effect,” with 20% increased probability of NEC per day of antibiotic exposure.