Abstract
OBJECTIVES: To explore risk factors for Stage-III necrotizing enterocolitis (NEC-III) in preterm neonates. METHODS: This was a retrospective case-control study of neonates born <33 weeks gestational age (GA) who were admitted to a tertiary neonatal intensive care unit, between 2015 and 2018. NEC-III cases were compared with Stage-II NEC (NEC-II) and non-NEC controls. Two to four non-NEC controls were matched by GA ± 1 week and date of birth ± 3 months, to one NEC-III case. Univariate and multivariate analyses were used to examine risk factors for NEC-III. RESULTS: Of 1360 neonates born <33 weeks, 71 (5.2%) had NEC-II and above, with 46% being NEC-III. Mean age of onset of NEC-III was 13.7 days versus 23.9 days for NEC-II (p = 0.01). Neonates with NEC-III were of lower GA (NEC-III 25.4 weeks, NEC-II 27.3 weeks, and non-NEC 26 weeks; p = 0.0008) and had higher Score for Neonatal Acute Physiology Perinatal Extension-II scores (NEC-III 47.5, NEC-II 28.4 and non-NEC 37, p = 0.003). Multivariate analysis showed duration of umbilical arterial catheter (UAC) >5 days was significantly associated with the development of NEC-III with adjusted odds ratio (AOR) 3.8; 95% confidence interval (CI) (1.05-13.66) for NEC-III versus non-NEC and AOR 5.57; 95% CI (1.65-18.73), p = 0.006 for NEC-III versus NEC-II. Rupture of membranes (ROM) >1 week was associated with NEC-III (AOR 6.93; 95% CI [1.56-30.69] vs. non-NEC and AOR 11.74; 95% CI [1.14-120.34] vs. NEC-II). CONCLUSION: The increased association of NEC-III with duration of UAC and ROM could be further examined in prospective studies, and an upper limit for UAC duration could be considered in NEC prevention bundles.