LEAD MOBILIZATION DURING PREGNANCY AND LACTATION IN URBAN WOMEN

病例报告表明，储存在骨骼中的铅在 怀孕和哺乳，将母亲，特别是 发育中的胎儿有铅中毒的风险。 胎盘完全 可渗透铅。 为了研究骨骼铅是 在怀孕和哺乳期间动员，我们提出了一个前瞻性队列， 一项研究，重复测量血液、血浆和骨铅， 不同种族的年轻市中心女性 我们假设 由于铅在怀孕和哺乳期间被调动， 胎儿血铅水平会升高，母体骨铅水平会 减少。 我们将比较骨，血浆和全血铅水平之前， 妊娠期间立即从同一妇女获得测量值 产后期和分娩后6个月。 我们假设 骨铅水平会下降，血铅水平会上升， 怀孕期间铅动员的结果。 在乳房发育的妇女中， 产后六个月的测量将评估任何额外的 哺乳对铅动员影响 类似的比较也将 在非妊娠女性的对照组中进行。 对照组将 使我们能够比较骨铅变化的自然历史， 没有怀孕和哺乳。 脐血铅水平 将确定评估母体转移的循环铅， 新生儿 预计该研究人群的体内铅负荷较高， 环境铅暴露的结果。 这其中的种族多样性 人口将使我们能够确定身体铅负担是否 在非洲裔美国人和西班牙裔女性中高于白人女性。 我们还将评估， 基线动员更多的铅比妇女与较低的基线体铅 负担 充足的铁储备已被证明可以防止铅的吸收 因此，可能防止铅移动， 怀孕 本研究将探讨铁储备对机体的影响 铅的负担有两种方式。 首先，我们将确定高铁是否 通过血清铁蛋白水平评估， 中铅的 其次，我们将确定是否铁店的水平 通过比较血清铁蛋白影响妊娠期铅动员 骨、血液和血浆铅水平测量前后 怀孕 这项研究将提供第一个定量检查的 假设骨骼铅动员发生在怀孕期间， 哺乳期调查应提供重要的见解， 慢性环境铅暴露对健康的潜在影响 孕妇、发育中的胎儿和婴儿通过母乳喂养。

Case reports suggest that lead stored in the skeleton is mobilized during pregnancy and lactation, placing the mother and, in particular, the developing fetus at risk of lead poisoning. The placenta is fully permeable to lead. To investigate the hypothesis that skeletal lead is mobilized during pregnancy and lactation, we propose a prospective cohort study with repeated measures of blood, plasma and bone lead in an ethnically diverse population of young, inner city women. We hypothesize that as lead is mobilized during pregnancy and lactation, maternal and fetal blood lead levels will increase and maternal bone lead levels will decrease. We will compare bone, plasma and whole blood lead levels prior to pregnancy with measurements obtained from the same women in the immediate postpartum period and six months after delivery. We hypothesize that bone lead levels will decrease and blood lead levels will increase as a result of lead mobilization during pregnancy. Among women who breast feed, the six month postpartum measurements will assess any additional effect of lactation on lead mobilization. Similar comparisons will also be made in a control group of non-pregnant women. The control group will allow us to compare the natural history of bone lead changes in the absence of pregnancy and lactation. Umbilical cord blood lead levels will be determined to assess maternal transfer of circulating lead to the neonate. This study population is expected to have a high body lead burden as a result of environmental lead exposure. The ethnic diversity of this population will enable us to determine whether body lead burdens are higher in African-American and Hispanic women than in Caucasian women. We will also assess whether women with higher body lead burden at baseline mobilize more lead than women with lower baseline body lead burden. Adequate iron stores have been shown to protect against lead absorption and therefore, possibly protect against lead mobilization during pregnancy. This study will investigate the effect of iron stores on body burden of lead in two ways. First, we will determine whether higher iron stores, assessed by serum ferritin levels, predict a lower body burden of lead. Secondly, we will determine whether the level of iron stores affects lead mobilization during pregnancy by comparing serum ferritin levels with bone, blood and plasma lead measurements before and after pregnancy. This study will provide the first quantitative examination of the hypothesis that skeletal lead mobilization occurs during pregnancy and lactation. The investigation should provide important insights into the potential health effects of chronic environmental lead exposure to pregnant women, developing fetuses and infants through breast feeding.