Flame Retardant and Adverse Perinatal Outcome (FRAPO)

描述（由申请人提供）：多溴二苯醚（PBDEs）是最普遍的有机污染物之一，在过去的40年里，它被广泛用作阻燃剂，特别是在美国和加拿大。因此，北美人的血液和母乳中多溴二苯醚的浓度是世界上最高的。多溴二苯醚存在于几乎所有孕妇的血浆中。它们也从胎盘、脐带、羊水和胎膜中分离出来，但它们对妊娠结局的影响尚不清楚。由于多溴二苯醚与甲状腺素（T4）和三碘甲状腺原氨酸（T3）结构相似，因此作为甲状腺系统内分泌干扰物被广泛研究。患有甲状腺功能减退症的妇女通过一种未知的机制增加了早产的风险，这是现代产科的首要问题。许多早产与胎盘和胎膜的炎症有关。越来越多的证据表明，在脓毒症动物模型中，甲状腺激素具有抗炎特性，可改善生存并减少原炎性细胞因子的产生。这可能是抑制T3和T4

DESCRIPTION (provided by applicant): Polybromated Diphenyl Ethers (PBDEs) are one of the most prevalent organic pollutants due to their wide- spread use during the past 40 years as flame retardants, especially in the United States and Canada. As a result, North Americans have the highest blood and breast milk concentrations of PBDEs anywhere in the world. PBDEs are present in the plasma of almost all pregnant women. They have also been isolated from the placenta, umbilical chord, amniotic fluid and fetal membranes but their effects on pregnancy outcome are unclear. PBDEs have been widely investigated as endocrine disruptors of the thyroid system due to their structural similarity with thyroxine (T4) and tri-iodothyronine (T3). Women with hypothyroidism are at increased risk for preterm birth, the foremost problem in modern obstetrics, through an unknown mechanism. Many preterm births are associated with inflammation in the placenta and fetal membranes. There is emerging evidence that thyroid hormones have anti-inflammatory properties, improving survival and reducing the production of proin- flammatory cytokines in animal models of sepsis. It is possible that inhibition of T3 and T4 bioactivity, by PBDEs increases the risk of pretem birth by favoring a pro-inflammatory environment. Our preliminary studies suggest that treatment of placental cultures with PBDE enhances the production of cytokines and prostaglandins associated with preterm birth. To determine if PBDE exposure may enhance the risk for preterm birth in women, we propose to collect blood samples from a women receiving prenatal care in southern California at each trimester of pregnancy. Samples from women who deliver preterm and 1000 randomly selected controls will be assayed for PBDE-47, the most prevalent conger detected in maternal plasma and thyroid-stimulating hormone (TSH). We hypothesize that women who deliver preterm will have increased concentrations of PBDE-47 throughout their pregnancy, especially when evidence of infection (histological chorioamnionitis) is present. Plasma PBDE-47 levels are expected to be positively correlated with plasma concentrations of TSH, suggesting reduced bioactivity of the thyroid hormones. This study will help fulfill the critical need to better understand the potential role of PBDEs, which were detectable in >90% of all pregnant women, on risk for adverse pregnancy outcomes.