Department of Public Health Sciences, Queen's University, Kingston, Ontario, Canada.
Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada.
BJOG. 2024 Apr;131(5):589-597. doi: 10.1111/1471-0528.17759. Epub 2024 Jan 18.
To study the association between maternal exposure to arsenic, cadmium, lead, manganese and mercury, time-to-pregnancy (TTP) and infertility.
Pregnancy-based retrospective TTP cohort study.
Hospitals and clinics from ten cities across Canada.
A total of 1784 pregnant women.
Concentrations of arsenic, cadmium, lead, manganese and mercury were measured in maternal whole blood during the first trimester of pregnancy as a proxy of preconception exposure. Discrete-time Cox proportional hazards models generated fecundability odds ratios (FOR) for the association between metals and TTP. Logistic regression generated odds ratios (OR) for the association between metals and infertility. Models were adjusted for maternal age, pre-pregnancy body mass index, education, income, recruitment site and plasma lipids.
TTP was self-reported as the number of months of unprotected intercourse to become pregnant. Infertility was defined as TTP longer than 12 months.
A total of 1784 women were eligible for the analysis. Mean ± SD maternal age and gestational age at interview were 32.2 ± 5.0 years, and 11.6 ± 1.6 weeks, respectively. Exposure to arsenic, cadmium, manganese or mercury was not associated with TTP or infertility. Increments of one standard deviation of lead concentrations resulted in a shorter TTP (adjusted FOR 1.09, 95% CI 1.02-1.16); however, the association was not linear when exposure was modelled in tertiles.
Blood concentrations of metals at typical levels of exposure among Canadian pregnant women were not associated with TTP or infertility. Further studies are needed to assess the role of lead, if any, on TTP.
研究母体暴露于砷、镉、铅、锰和汞与妊娠时间（TTP）和不孕之间的关系。
基于妊娠的回顾性 TTP 队列研究。
加拿大十个城市的医院和诊所。
共有 1784 名孕妇。
在妊娠早期，通过测量母体全血中的砷、镉、铅、锰和汞浓度来代表受孕前的暴露情况。离散时间 Cox 比例风险模型生成金属与 TTP 之间关联的生育能力比值比（FOR）。Logistic 回归生成金属与不孕之间关联的比值比（OR）。模型调整了母亲的年龄、孕前体重指数、教育程度、收入、招募地点和血脂。
TTP 由未采取保护措施的受孕月数自行报告。不孕定义为 TTP 超过 12 个月。
共有 1784 名女性符合分析条件。平均（±SD）母亲年龄和访谈时的孕龄分别为 32.2±5.0 岁和 11.6±1.6 周。暴露于砷、镉、锰或汞与 TTP 或不孕无关。铅浓度的一个标准差增量导致 TTP 缩短（校正后的 FOR 为 1.09，95%CI 为 1.02-1.16）；然而，当以三分位数模型暴露时，这种关联不是线性的。
在加拿大孕妇典型暴露水平下，血液中金属浓度与 TTP 或不孕无关。需要进一步研究以评估铅（如果有的话）对 TTP 的作用。
