Effect of chorioamnionitis on necrotizing enterocolitis in preterm infants: a multicenter cohort study

Xin Guo¹Jiaming Xian¹Xianhong Chen^2,3Meifen Li⁴Fengji Lin¹Defei Ma¹Rongrong Zhang¹Guichao Zhong⁵Huiying Tu⁵Shujuan Zeng³Houxin Kang⁶Ya Pan⁷Xiaoli Li⁷Xueli Zhang⁸Zhangxing Wang⁸Hanni Lin⁹Shihua Yuan⁹Jing Han^1*

• ¹Department of Neonatology, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City (Longgang Maternity and Child Institute of Shantou University Medical College), Shenzhen, China
• ²Shenzhen Clinical Medical College, Guangzhou University of Chinese Medicine, Shenzhen, China
• ³Division of Neonatology, Longgang Central Hospital of Shenzhen, Shenzhen, China
• ⁴Department of Pediatrics, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City (Longgang Maternity and Child Institute of Shantou University Medical College), Shenzhen, China
• ⁵Department of Neonatology, Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, First Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
• ⁶Neonatal·Child Critical Child Health Care Division, The Central Hospital of Enshi Tujia and Miao Autonomous Prefecture, Enshi Tujia and Miao Autonomous Prefecture, China
• ⁷Neonatal Department, Shenzhen Longhua Maternity and Child Healthcare Hospital, Shenzhen, China
• ⁸Division of Neonatology, Shenzhen Longhua People’s Hospital, Shenzhen, China
• ⁹Department of Neonatology, Shenzhen Luohu People’s Hospital, Shenzhen, China

Background: To explore the association between maternal chorioamnionitis (CAM) exposure and necrotising enterocolitis (NEC) in very preterm infants (VPI) or very low birth weight (VLBWI).The aim of this multicentre cohort study was to investigate the impact of maternal CAM and its different staging on VPI or VLBWI NEC in six medical centres in Shenzhen between 2022 and 2023. The primary outcome was NEC (Bell staging ≥ II) and secondary outcomes included NEC or in-hospital mortality. Logistic regression adjusted for confounders identified through directed acyclic graphs (DAG) and literature review. The interaction effect of premature rupture of membranes was assessed using stratification and likelihood ratio tests.In the cohort study, the prevalence of CAM was 44.31%, the prevalence of NEC was 5.38%, and the prevalence of NEC or death was 7.69%. Of the 288 participants whose mothers had been exposed to CAM, 1.04% had clinical CAM, 96.53% had histological CAM, and 2.43% were diagnosed with confirmed CAM. CAM was associated with NEC or death (aOR = 1.90, 95% CI 1.02-3.55); the confirmed CAM group showed a stronger association (aOR = 7.14, 95% CI 1. 20-42.35). In preterm infants, CAM was significantly associated with NEC or death in cases of preterm membrane rupture (aOR = 2.18, 95% CI 1.07-4.44).Conclusions: There was a significant positive association between CAM and NEC or death in VLBWs or VPIs, which was mainly from the population with confirmed CAM. In premature rupture of membranes, the association between CAM and NEC or death was more significant.