Environmental exposure to phthalates and bisphenol A (BPA) may have endocrine disrupting effects that alter length of gestation. We assessed the association between the urinary concentrations of 11 phthalate metabolites and BPA with length of gestation in a cohort of women followed from before conception with daily 1st-morning urinary hormone measures that identified day of implantation. Pre-implantation and post-implantation urinary phthalate metabolites and BPA concentrations were measured in pooled urine samples designed to limit single-measure variability due to the likely episodic nature of these exposures and the short half-life of these compounds. We estimated associations between these exposure biomarkers early in pregnancy with length of gestation from implantation to spontaneous birth. Cox proportional hazards models were used to estimate the hazard of birth among 125 naturally-conceived, singleton live births with censoring for medical interventions that artificially shortened pregnancy. Higher concentrations of mono (2-ethyl-5-hydroxyhexyl) phthalate (a metabolite of di (2-ethylhexyl) phthalate (DEHP)) during the pre-implantation window were associated with reduced probability of birth, i.e., longer gestations (hazard ratio (HR): 0.55, 95% CI: 0.35, 0.86; p = 0.01). The HR for the molar sum of the four DEHP metabolites measured showed a similar association (HR: 0.67, 95% CI: 0.43, 1.05). Higher concentrations of mono (3-carboxypropyl) phthalate (MCPP), a non-specific metabolite of several high molecular-weight phthalates, measured post-implantation were associated with increased risk of earlier birth, i.e. shorter length of gestation, HR: 1.59, CI: 1.02, 2.49. Early gestational exposure to DEHP and possibly other high-molecular weight phthalates, (as reflected by urinary MCPP concentrations) may influence the length of pregnancy. Such effects could have consequences for neonatal and maternal health.

中文翻译：

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妊娠早期邻苯二甲酸酯代谢物和双酚A的尿液浓度与妊娠时间的关系

环境暴露于邻苯二甲酸盐和双酚A（BPA）可能具有内分泌干扰作用，从而改变妊娠时间。我们评估了一组女性中11种邻苯二甲酸酯代谢物的尿液浓度和BPA与妊娠期之间的关系，从受孕之前开始，每天进行第一次早晨尿液激素测量，以确定植入的一天。在植入前和植入后尿邻苯二甲酸酯代谢物和BPA浓度在汇集的尿液样本中进行了测量，这些样本旨在限制单次测量的可变性，因为这些暴露的可能是情节性的，并且这些化合物的半衰期很短。我们估计了妊娠初期这些暴露生物标志物与从植入到自然出生的妊娠时间之间的关联。使用Cox比例风险模型评估了125个自然构思的单身活产婴儿的出生危险，并对其进行了人工干预以缩短怀孕的医疗干预措施进行审查。植入前窗口期间邻苯二甲酸单（2-乙基-5-羟基己基）酯（邻苯二甲酸二（2-乙基己基）的代谢产物）的较高浓度与降低的出生概率相关，即妊娠时间更长（危险比） （HR）：0.55，95％CI：0.35，0.86； p ＝ 0.01）。所测量的四种DEHP代谢物的摩尔总和的HR显示出相似的相关性（HR：0.67，95％CI：0.43，1.05）。植入后测得的较高浓度的邻苯二甲酸单（3-羧丙基）酯（MCPP）（几种高分子量邻苯二甲酸酯的非特异性代谢产物）与早产的风险增加相关，即 妊娠期较短，HR：1.59，CI：1.02，2.49。妊娠早期暴露于DEHP和可能的其他高分子量邻苯二甲酸酯（如尿中MCPP浓度所反映）可能会影响怀孕时间。这种影响可能会对新生儿和孕产妇健康产生影响。