Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, United States.
Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, United States; Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States.
Environ Res. 2019 Feb;169:131-138. doi: 10.1016/j.envres.2018.10.037. Epub 2018 Nov 1.
Preterm birth continues to be a significant public heath concern and is a leading cause of perinatal and infant mortality. Environmental exposures to phenols and parabens are suspected to potentially contribute to the pathology of preterm birth, yet limited human studies have characterized the extent to which these toxicants are associated with birth outcomes.
We examined the associations between phenols, parabens, and preterm birth, within pregnant women who were recruited early in gestation into the LIFECODES cohort at Brigham and Women's Hospital in Boston, Massachusetts. Urine samples were collected at up to 4 time points in pregnancy and analyzed for phenols and parabens. We selected 130 cases of preterm birth (defined as delivery before 37 weeks gestation), and 350 random controls. We categorized preterm birth subtypes based on clinical presentation and identified 75 cases of spontaneous preterm birth (characterized by spontaneous preterm labor and/or preterm premature rupture of membranes), and 37 cases of placental preterm birth (characterized by preeclampsia and/or intrauterine growth restriction). We used multivariate logistic regression with visit specific and geometric averages of phenols and parabens to determine associations with preterm birth.
We observed moderate variability in urinary phenol and paraben concentrations over pregnancy with intraclass correlation coefficients ranging between 0.45 and 0.68. Regression analyses indicated mostly null associations. We observed inverse associations, notably between 2,5-dichlorophenol and overall preterm birth (adjusted odds ratio [95% confidence interval, CI]: 0.79 [0.67 - 0.94]), and this relationship was consistent by study visit. Conversely, ethyl paraben was associated with increased risk for placental preterm birth (adjusted odds ratio [95% CI]: 1.47 [1.14 - 1.91]). Bisphenol-S detection at visit 4 was associated with overall preterm birth (adjusted odds ratio [95% CI]: 2.05 [1.09, 3.89]).
While the findings from this study largely indicate null associations, we observed some relationships between select phenols, parabens and preterm birth, which warrants further investigation of these toxicants and birth outcomes.
早产仍是一个重大的公共卫生问题，也是围产期和婴儿死亡的主要原因。酚类和对羟基苯甲酸酯类等环境污染物可能会导致早产，然而，很少有人类研究描述了这些有毒物质与出生结局的关联程度。
我们在马萨诸塞州波士顿的布里格姆妇女医院的 LIFECODES 队列中，在妊娠早期招募了孕妇，研究了酚类物质、对羟基苯甲酸酯类物质与早产之间的关系。我们在妊娠的多达 4 个时间点采集了尿液样本，并分析了其中的酚类物质和对羟基苯甲酸酯类物质。我们选择了 130 例早产（定义为分娩前 37 周）病例和 350 例随机对照。我们根据临床表现对早产亚型进行分类，并确定了 75 例自发性早产（特征为自发性早产临产和/或早产胎膜早破）和 37 例胎盘性早产（特征为子痫前期和/或宫内生长受限）。我们使用具有访问特异性和酚类物质和对羟基苯甲酸酯类物质的几何平均值的多变量逻辑回归来确定与早产的关联。
我们观察到妊娠期间尿液中酚类物质和对羟基苯甲酸酯类物质的浓度存在中度变异性，组内相关系数在 0.45 到 0.68 之间。回归分析表明，大多数情况下没有关联。我们观察到了相反的关联，特别是在 2,5-二氯苯酚和总体早产之间（调整后的优势比[95%置信区间，CI]：0.79[0.67-0.94]），这种关系在各次就诊时都是一致的。相反，乙基对羟基苯甲酸酯与胎盘性早产的风险增加相关（调整后的优势比[95%CI]：1.47[1.14-1.91]）。在第 4 次就诊时检测到双酚 S 与总体早产相关（调整后的优势比[95%CI]：2.05[1.09, 3.89]）。
尽管这项研究的结果主要表明没有关联，但我们观察到一些特定的酚类物质、对羟基苯甲酸酯类物质与早产之间的关系，这需要进一步研究这些有毒物质与出生结局之间的关系。
