Prenatal exposure to air pollutants and neonatal necrotizing enterocolitis: Identifying critical gestational windows...

Although Emerging evidence indicates that prenatal air pollution exposure may harm neonatal health, but its link to necrotizing enterocolitis (NEC) remains unclear. This retrospective cohort study investigated 219 neonates admitted to Zhujiang Hospital between 2014 and 2024. Infants were stratified by Bell staging, with stage I as controls and stages II-III as the disease group. Prenatal exposure data for their mothers were obtained by linking to the electronic medical record system. A Cox proportional hazards model was used to examine the association between prenatal exposure to PM_2.5, PM₁₀, NO₂, SO₂ and NEC, with results expressed as adjusted hazard ratios (HRs). Significant associations were observed between maternal exposure to specific pollutants and NEC risk, with the first and second trimesters identified as particularly vulnerable periods. Specifically, per 1 μg/m³ increase in first-trimester PM₁₀ exposure was associated with a significantly increased risk of NEC (HR: 1.009, 95 % CI: 1.000-1.018), and a corresponding increase in second-trimester NO₂ exposure also significantly elevated the risk (HR: 1.037, 95 % CI: 1.002-1.073). Notably, prenatal SO₂ exposure was significantly associated with an increased NEC risk across all trimesters and the entire pregnancy (P < 0.05). Subgroup analyses revealed the strongest effects for PM₁₀, NO₂, and SO₂ in spring, winter, and summer, respectively. Our findings underscore the importance of environmental factors in NEC etiology, pinpointing critical gestational windows of susceptibility. Reducing maternal exposure to SO₂ and NO₂ during pregnancy may mitigate NEC risk, highlighting the public health relevance of air quality management for vulnerable populations.