Dzierlenga Michael W, Crawford Lori, Longnecker Matthew P
Environment & Health, Ramboll, NC.
Environ Epidemiol. 2020 Apr 23;4(3):e095. doi: 10.1097/EE9.0000000000000095. eCollection 2020 Jun.
Perfluorooctane sulfonic acid (PFOS) is a ubiquitous environmental contaminant. Most people in developed countries have detectable serum concentrations. Lower birth weight has been associated with serum PFOS in studies world-wide, many of which have been published only recently.
To facilitate a causal assessment of the birth weight and PFOS association, we updated previous meta-analyses of the association and employed a method that facilitated inclusion of all available data in one analysis. Our analysis was based on observations from 29 studies.
The random effects summary was -3.22 g/ng/ml (95% confidence interval [CI] = -5.11, -1.33). In a subgroup analysis stratified by when in pregnancy the PFOS concentration was measured, the summary for the early group was -1.35 (95% CI = -2.33, -0.37) and for the later group was -7.17 (95% CI = -10.93, -3.41). In a meta-regression model including a term for timing of blood draw, the intercept was slightly positive but essentially zero (0.59 g/ng/ml, 95% CI = -1.94, 3.11). In other words, the model indicated that when blood was drawn at the very beginning of pregnancy, there was essentially no relation of birth weight to PFOS. The results from the subgroup analyses differed from those from the model because the average gestational age at blood draw in the early group was 14 weeks, when bias would still be expected. A stronger inverse association in Asian studies was not completely explained by their blood draws being from later in pregnancy.
The evidence was weakly or not supportive of a causal association.
全氟辛烷磺酸（PFOS）是一种普遍存在的环境污染物。发达国家的大多数人血清中都可检测到其浓度。在全球范围内的研究中，低出生体重与血清PFOS有关，其中许多研究直到最近才发表。
为便于对出生体重与PFOS之间的关联进行因果评估，我们更新了先前对该关联的荟萃分析，并采用了一种便于在一次分析中纳入所有可用数据的方法。我们的分析基于29项研究的观察结果。
随机效应汇总值为-3.22克/纳克/毫升（95%置信区间[CI]=-5.11，-1.33）。在按测量PFOS浓度的孕期时间分层的亚组分析中，早期组的汇总值为-1.35（95%CI=-2.33，-0.37），后期组的汇总值为-7.17（95%CI=-10.93，-3.41）。在一个包含采血时间项的元回归模型中，截距略为正值但基本为零（0.59克/纳克/毫升，95%CI=-1.94，3.11）。换句话说，该模型表明在孕期刚开始时采血，出生体重与PFOS基本没有关系。亚组分析的结果与模型的结果不同，因为早期组采血时的平均孕周为14周，此时仍可能存在偏倚。亚洲研究中更强的负相关不能完全由其采血时间较晚来解释。
证据对因果关联的支持较弱或不支持。
