Epidemiology Branch, National Institute of Environmental Health Sciences, 111 T W Alexander Drive, Mailstop A3-05, Research Triangle Park, NC, 27709, USA.
Biostatistics Branch, National Institute of Environmental Health Sciences, 111 T W Alexander Drive, Research Triangle Park, NC, 27709, USA.
Environ Health. 2019 Aug 30;18(1):80. doi: 10.1186/s12940-019-0522-2.
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.
环境暴露于邻苯二甲酸酯和双酚 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 11 种邻苯二甲酸酯代谢物和 BPA 的尿液浓度与受孕前每天采集的晨尿激素测量值确定着床日的队列中妇女妊娠时间的关系。
在受孕前和受孕后收集尿液样本，以测量尿液中的邻苯二甲酸酯代谢物和 BPA 浓度。这些样本通过设计来限制单次测量的变异性，因为这些暴露可能具有偶发性，并且这些化合物的半衰期较短。我们使用 Cox 比例风险模型来估计妊娠早期这些暴露生物标志物与从着床到自然分娩的妊娠时间之间的关系。该模型用于 125 例自然受孕、单胎活产的自然分娩风险估计，对因医疗干预而人为缩短妊娠的情况进行了随访。
在受孕前窗口期，较高浓度的单（2-乙基-5-羟基己基）邻苯二甲酸酯（邻苯二甲酸二（2-乙基己基）酯（DEHP）的代谢物）与出生概率降低，即妊娠时间延长有关（风险比（HR）：0.55，95%置信区间（CI）：0.35，0.86；p=0.01）。测量的四种 DEHP 代谢物的摩尔总和的 HR 显示出类似的关联（HR：0.67，95%CI：0.43，1.05）。在受孕后测量的较高浓度的单（3-羧基丙基）邻苯二甲酸酯（MCPP）是几种高分子量邻苯二甲酸酯的非特异性代谢物，与更早出生的风险增加相关，即妊娠时间更短，HR：1.59，CI：1.02，2.49。
早期妊娠暴露于 DEHP 和可能其他高分子量邻苯二甲酸酯（反映在尿液 MCPP 浓度中）可能会影响妊娠时间。这些影响可能对新生儿和产妇健康产生影响。
