Abstract
Necrotizing enterocolitis (NEC) is a common causes of morbidity and mortality in NICUs. Prolonged duration of empiric antibiotic therapy alters the normal gut flora and may increase the risk of NEC; however, such an association needs to be investigated in larger cohorts.
To examine the association between the duration of antibiotic exposure and the development of stage 2 or 3 NEC in very preterm neonates.
A retrospective case-control study of neonates born at <29 weeks and admitted between 2010 and 2013 was conducted using data from the Canadian Neonatal Network. Infants were excluded if they had culture-proven sepsis. Baseline demographics were compared between those who developed NEC and those who did not. The number of NPO and empiric antibiotic days until the development of NEC were calculated for cases and compared with those for the two controls (GA, birth weight and sex-matched) in each cluster for the same postnatal age at which each case developed NEC.
A total of 224 cases of NEC and 447 controls were studied. There were no differences in chorioamnionitis, SNAP-II scores, PDA or inotrope use between those who developed NEC and those who did not. A multiple regression analysis controlling for NPO days and antenatal steroid use revealed that the duration of antibiotic exposure was higher in the NEC cases as compared with controls (P<0.01). Antibiotic treatment of more than four days was associated with significantly higher adjusted odds ratios of NEC.
Empiric antibiotic exposure of more than four days in very preterm neonates of <29 weeks was associated with an increased risk of NEC after controlling for confounders. Further prospective studies on reasons for empiric usage of antibiotics and its association with neonatal morbidities is warranted.
