Umbilical arterial catheter duration as risk factor for Bell's Stage III necrotizing enterocolitis in preterm neonates

To explore risk factors for Stage‐III necrotizing enterocolitis (NEC‐III) in preterm neonates.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.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).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.