Karmaus Wilfried, Zhu Xiaobei
Department of Epidemiology, Michigan State University, 4660 S, Hagadorn Rd, Suite 600, East Lansing, MI 48823, USA.
Environ Health. 2004 Jan 28;3(1):1. doi: 10.1186/1476-069X-3-1.
Studies on maternal exposure to polychlorinated biphenyls (PCBs) reported inconsistent findings regarding birth weight: some studies showed no effect, some reported decreased birth weight, and one study found an increase in weights. These studies used different markers of exposure, such as measurement of PCBs in maternal serum or questionnaire data on fish consumption. Additionally maternal exposures, such as dichlorodiphenyl-dichloroethylene (DDE), which are related to PCB exposure and may interfere with the PCB effect, were rarely taken into account.
Between 1973 and 1991, the Michigan Department of Community Health conducted three surveys to assess PCB and DDE serum concentrations in Michigan anglers. Through telephone interviews with parents, we gathered information on the birth characteristics of their offspring, focusing on deliveries that occurred after 1968. We used the maternal organochlorine (OC) measurement closest to the date of delivery as the exposure. Although one mother may have contributed more than one child, serum concentrations derived from measurements in different surveys could vary for different children from the same mother. The maternal DDE and PCB serum concentrations were categorized as follows: 0 -< 5 microg / L, 5 -< 15 microg / L, 15 -< 25 microg / L, >or=25 microg / L. Using repeated measurement models (Generalized Estimation Equation), we estimated the adjusted mean birth weight controlling for gender, birth order, gestational age, date of delivery as well as maternal age, height, education, and smoking status.
We identified 168 offspring who were born after 1968 and had maternal exposure information. We found a reduced birth weight for the offspring of mothers who had a PCB concentration >or=25 microg / L (adjusted birth weight = 2,958 g, p = 0.022). This group, however, was comprised of only seven observations. The association was not reduced when we excluded preterm deliveries. The birth weight of offspring was increased in women with higher DDE concentrations when controlling for PCBs; however, this association was not statistically significant.
Our results contribute to the body of evidence that high maternal serum PCB concentration may reduce the birth weight in offspring. However, only a small proportion of mothers may actually be exposed to PCB concentrations >or=25 microg / L.
关于母亲接触多氯联苯（PCBs）对出生体重影响的研究结果并不一致：一些研究显示无影响，一些报告出生体重下降，还有一项研究发现体重增加。这些研究使用了不同的接触标志物，如母亲血清中多氯联苯的测量值或鱼类消费的问卷调查数据。此外，很少考虑与多氯联苯接触相关且可能干扰多氯联苯效应的其他母亲接触物质，如二氯二苯二氯乙烯（DDE）。
1973年至1991年间，密歇根州社区卫生部进行了三项调查，以评估密歇根州垂钓者血清中的多氯联苯和DDE浓度。通过电话采访父母，我们收集了他们后代的出生特征信息，重点关注1968年以后的分娩情况。我们将最接近分娩日期的母亲有机氯（OC）测量值用作接触指标。尽管一位母亲可能生育不止一个孩子，但来自不同调查测量的血清浓度对于同一母亲的不同孩子可能会有所不同。母亲的DDE和多氯联苯血清浓度分类如下：0 -<5微克/升、5 -<15微克/升、15 -<25微克/升、≥25微克/升。使用重复测量模型（广义估计方程），我们在控制性别、出生顺序、孕周、分娩日期以及母亲年龄、身高、教育程度和吸烟状况的情况下，估计了调整后的平均出生体重。
我们确定了168名1968年以后出生且有母亲接触信息的后代。我们发现，母亲多氯联苯浓度≥25微克/升的后代出生体重降低（调整后的出生体重 = 2958克，p = 0.022）。然而，这一组仅包含7个观察对象。当我们排除早产时，这种关联并未减弱。在控制多氯联苯的情况下，DDE浓度较高的女性所生后代的出生体重增加；然而，这种关联在统计学上并不显著。
我们的结果为高母亲血清多氯联苯浓度可能降低后代出生体重这一证据提供了补充。然而，实际上只有一小部分母亲可能接触到≥25微克/升的多氯联苯浓度。
