Adverse pregnancy outcomes entail a large health burden for the mother and offspring; a part of it might be avoided by better understanding the role of environmental factors in their etiology. Our aims were to review the assessment tools to characterize fecundity troubles and pregnancy-related outcomes in human populations and their sensitivity to environmental factors. For each outcome, we reviewed the possible study designs, main sources of bias, and their suggested cures. In terms of study design, for most pregnancy outcomes, cohorts with recruitment early during or even before pregnancy allow efficient characterization of pregnancy-related events, time-varying confounders, and in utero exposures that may impact birth outcomes and child health. Studies on congenital anomalies require specific designs, assessment of anomalies in medical pregnancy terminations, and, for congenital anomalies diagnosed postnatally, follow-up during several months after birth. Statistical analyses should take into account environmental exposures during the relevant time windows; survival models are an appropriate approach for fecundity, fetal loss, and gestational duration/preterm delivery. Analysis of gestational duration could distinguish pregnancies according to delivery induction (and possibly pregnancy-related conditions). In conclusion, careful design and analysis are required to better characterize environmental effects on human reproduction.

中文翻译：

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研究环境因素对生育力和妊娠相关结果的影响的流行病学工具。

不利的妊娠结局会给母亲和后代带来巨大的健康负担；通过更好地了解环境因素在其病因中的作用，可以避免其中的一部分。我们的目标是审查评估工具，以表征人类群体的生育问题和妊娠相关结果及其对环境因素的敏感性。对于每个结果，我们审查了可能的研究设计、偏倚的主要来源及其建议的治疗方法。在研究设计方面，对于大多数妊娠结局，在妊娠早期甚至妊娠前招募的队列可以有效表征妊娠相关事件、随时间变化的混杂因素以及可能影响出生结局和儿童健康的宫内暴露。先天性异常的研究需要特定的设计，对医学终止妊娠的异常情况进行评估，对于出生后诊断出的先天性异常，在出生后几个月内进行随访。统计分析应考虑相关时间窗口内的环境暴露；生存模型是生育力、胎儿丢失和妊娠持续时间/早产的合适方法。妊娠持续时间分析可以根据分娩诱导（以及可能与妊娠相关的情况）区分妊娠。总之，需要仔细设计和分析以更好地表征环境对人类繁殖的影响。生存模型是生育力、胎儿丢失和妊娠持续时间/早产的合适方法。妊娠持续时间分析可以根据分娩诱导（以及可能与妊娠相关的情况）区分妊娠。总之，需要仔细设计和分析以更好地表征环境对人类繁殖的影响。生存模型是生育力、胎儿丢失和妊娠持续时间/早产的合适方法。妊娠持续时间分析可以根据分娩诱导（以及可能与妊娠相关的情况）区分妊娠。总之，需要仔细设计和分析以更好地表征环境对人类繁殖的影响。