Biosanitary Research Institute of Granada (ibs.GRANADA), University Hospitals of Granada, Spain; Center for Biomedical Research (CIBM), University of Granada, Spain; Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), 18100, Spain.
Department of Environmental Health, Harvard T.H. Chan School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA.
Environ Res. 2019 Feb;169:272-279. doi: 10.1016/j.envres.2018.11.022. Epub 2018 Nov 17.
Phthalates are known reproductive toxicants that reduce placental and fetal weight in experimental animal studies. Although phthalate exposure has been associated with reduced birth weight in humans, there is limited epidemiologic evidence on whether the placenta is also affected.
To assess whether maternal and paternal preconception and prenatal urinary phthalate metabolite concentrations are associated with placental weight, and the birth weight: placental weight (BW:PW) ratio among singletons conceived by subfertile couples.
The present analysis included 132 mothers and 68 fathers, and their corresponding 132 singletons recruited in an academic hospital fertility center in Boston, Massachusetts. Urinary concentrations of eleven phthalate metabolites were measured and averaged in multiple paternal (n = 196) and maternal (n = 596) preconception, and maternal prenatal (n = 328) samples. Placental weight and birth weight (grams) were abstracted from delivery records, and the BW:PW was calculated. We estimated the association of natural log-phthalate metabolite concentrations across windows of exposure with placental weight and the BW:PW ratio using multivariable linear regression models, adjusting for a priori covariates.
In adjusted models, each log-unit increase in paternal urinary concentrations of the sum of di-(2-ethylhexyl) phthalate (ΣDEHP) metabolites was associated with a 24 g (95% CI: -48, -1) decrease in placental weight. We also observed a significant negative association between maternal preconception monoethyl phthalate (MEP) metabolite concentrations and the BW:PW ratio (β = -0.26; 95%CI: -0.49, -0.04). Additionally, each log-unit increase in prenatal MEP metabolite concentrations was associated with a 24 g (95% CI: -41, -7) decrease in placental weight.
Our results suggest that certain paternal and maternal urinary phthalate metabolites may affect placental weight and the BW:PW ratio. However, given the small sample size within a subfertile cohort and the novelty of these findings, more studies are needed to confirm the present results.
邻苯二甲酸酯是已知的生殖毒物，在实验动物研究中会降低胎盘和胎儿的体重。尽管邻苯二甲酸酯暴露与人类的出生体重降低有关，但关于胎盘是否也受到影响的流行病学证据有限。
评估母体和父体孕前和孕期尿液中邻苯二甲酸酯代谢物浓度是否与胎盘重量以及不孕夫妇所生育的单胎婴儿的出生体重与胎盘重量之比（BW:PW）有关。
本分析纳入了马萨诸塞州波士顿一家学术医院生育中心招募的 132 名母亲和 68 名父亲及其相应的 132 名单胎婴儿。测量并平均了 196 份父体和 596 份母体孕前以及 328 份母体孕期尿液中 11 种邻苯二甲酸酯代谢物的浓度。从分娩记录中提取胎盘重量和出生体重（克），并计算 BW:PW。我们使用多变量线性回归模型，根据先验协变量，估计在暴露窗口期内邻苯二甲酸酯代谢物浓度自然对数值与胎盘重量和 BW:PW 比值之间的关联。
在调整后的模型中，父体尿液中ΣDEHP 代谢物总和每增加一个对数单位，胎盘重量就会减少 24 克（95%CI：-48，-1）。我们还观察到母体孕前 MEP 代谢物浓度与 BW:PW 比值呈显著负相关（β= -0.26；95%CI：-0.49，-0.04）。此外，母体孕期 MEP 代谢物浓度每增加一个对数单位，胎盘重量就会减少 24 克（95%CI：-41，-7）。
我们的研究结果表明，某些父体和母体尿液中的邻苯二甲酸酯代谢物可能会影响胎盘重量和 BW:PW 比值。然而，考虑到不孕夫妇队列的样本量较小且这些发现具有新颖性，需要进行更多研究来证实本研究结果。
