Department of Obstetrics and Gynecology, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, PR China.
J Matern Fetal Neonatal Med. 2022 Oct;35(19):3700-3706. doi: 10.1080/14767058.2020.1837772. Epub 2020 Oct 27.
Evidence on the relationship between prenatal exposure to NO and CO and spontaneous abortion (SAB) is insufficient. We investigated whether there is an association between maternal exposure to nitrogen dioxide (NO) and carbon monoxide (CO) before and during pregnancy and SAB.
We conducted a case-control study using medical records of 2445 pregnant women who admitted for abortion prior to 20 weeks of gestational age from January 2014 to December 2019 at a tertiary-care hospital in Shanghai, China. Of the 2445 participants, 1075 were SAB cases and 1370 were healthy controls (underwent elective abortions). Maternal exposure to NO and CO before and during pregnancy was estimated using daily air pollution concentration data. Multivariable logistic regression models were constructed to quantify the relationships between maternal exposure to NO or CO and the risk of SAB while controlling for potential confounders.
NO exposure levels during pregnancy were significantly higher in SAB cases than in healthy controls (42.26 vs. 40.67, < .01). NO exposure during pregnancy was positively associated with the risk of SAB. An interquartile range (16 μg/m) increase in NO exposure was associated with 68% increase in the odds of SAB (OR = 1.68, 95% CI, 1.28, 2.21). Analyses of associations by quartile of NO exposure showed that elevated NO exposure during pregnancy was associated with increased odds of SAB in linear dose-response manners. Compared with the lowest quartile of NO exposure, the odds of SAB in the fourth quartile of NO exposure increased 61% (OR = 1.61, 95% CI, 1.03-2.53). No associations of CO exposure with SAB risk were observed.
Our study suggested that exposure to NO during early pregnancy was associated with increased risk of SAB. Further studies are needed to confirm our results and explore the potential biological mechanism underlying these associations.
关于产前暴露于二氧化氮（NO）和一氧化碳（CO）与自然流产（SAB）之间的关系，证据不足。我们调查了母亲在妊娠前和妊娠期间暴露于二氧化氮（NO）和一氧化碳（CO）与 SAB 之间是否存在关联。
我们进行了一项病例对照研究，纳入了 2014 年 1 月至 2019 年 12 月期间在中国上海一家三级保健医院因妊娠 20 周前人工流产的 2445 名孕妇的病历记录。在 2445 名参与者中，1075 例为 SAB 病例，1370 例为健康对照（行择期人工流产）。使用每日空气污染浓度数据来估计妊娠前和妊娠期间母亲暴露于 NO 和 CO 的情况。构建多变量逻辑回归模型来量化母亲暴露于 NO 或 CO 与 SAB 风险之间的关系，同时控制潜在的混杂因素。
SAB 病例的妊娠期间 NO 暴露水平明显高于健康对照组（42.26 对 40.67，<0.01）。妊娠期间的 NO 暴露与 SAB 风险呈正相关。NO 暴露每增加一个四分位距（16μg/m），SAB 的比值比（OR）增加 68%（OR=1.68，95%CI，1.28，2.21）。按 NO 暴露四分位数进行的关联分析表明，妊娠期间升高的 NO 暴露与 SAB 风险呈线性剂量反应关系。与 NO 暴露最低四分位数相比，NO 暴露第四四分位数的 SAB 比值比增加了 61%（OR=1.61，95%CI，1.03-2.53）。CO 暴露与 SAB 风险无关联。
我们的研究表明，妊娠早期暴露于 NO 与 SAB 风险增加有关。需要进一步的研究来证实我们的结果，并探索这些关联背后的潜在生物学机制。
