As far as we know, there have been no studies exploring the association between maternal sulfur dioxide (SO₂) exposure and the risk of hypospadias in offspring. We aimed to evaluate this association during the 3 months before conception and the first trimester. A population-based case–control study was conducted in male infants, consisting of 348 cases of hypospadias and 4023 controls. Maternal exposure to SO₂, particulate matter with aerodynamic diameters ≤10 μm (PM₁₀), and nitrogen dioxide (NO₂) was assessed by averaging the concentrations recorded at all stations in the mother's city of residence. Air pollutants were tested for multicollinearity using variance inflation factor analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by multivariable logistic regression models. SO₂ exposure during the 3 months before conception was significantly associated with the risk of hypospadias (highest tertile: OR = 7.40, 95% CI: 3.54–15.62). When focusing on shorter exposure windows, similar associations were observed for SO₂ exposure in the first and second month before and the first month after conception. In conclusion, maternal exposure to SO₂ during the 3 months before and the first and second months after conception may increase the risk of hypospadias in offspring.

中文翻译：

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母体受孕前后二氧化硫暴露及后代尿道下裂风险

据我们所知，还没有研究探讨母体二氧化硫 (SO ₂ ) 暴露与后代尿道下裂风险之间的关系。我们旨在评估受孕前 3 个月和妊娠早期的这种关联。一项基于人群的病例对照研究在男婴中进行，包括 348 例尿道下裂和 4023 例对照。母亲暴露于 SO ₂、空气动力学直径≤10 μm 的颗粒物 (PM ₁₀ ) 和二氧化氮 (NO ₂) 是通过平均在母亲居住城市的所有站点记录的浓度来评估的。使用方差膨胀因子分析测试空气污染物的多重共线性。优势比 (OR) 和 95% 置信区间 (CI) 通过多变量逻辑回归模型计算。受孕前 3 个月内SO ₂暴露与尿道下裂的风险显着相关（最高三分位数：OR = 7.40，95% CI：3.54–15.62）。当关注较短的暴露窗口时，在受孕前的第一个月和第二个月以及受孕后的第一个月观察到 SO ₂暴露的类似关联。总之，母体暴露于 SO ₂ 在受孕前 3 个月和受孕后的第一和第二个月可能会增加后代尿道下裂的风险。