THYROID ANTIBODIES AS A RISK FACTOR FOR TRISOMY BIRTHS

有大量的流行病学证据表明， 出生患有唐氏综合征或其他三体的儿童 这些患者的血清中存在甲状腺抗体 孩子的父母。此类研究的案例选自 患有该综合征的儿童或成人在 生命最早的几年。如果甲状腺抗体是糖尿病的危险因素 染色体不分离，那么这些抗体应该是 在受孕时存在于父代中；否则为 关联可能是由于对幸存者的选择偏见，这些幸存者 改变的免疫系统可以起到保护作用。 我们将检验甲状腺抗体之间存在关联的假设。 在一项病例对照研究中发现了三体出生，其中所有病例和 对照组在出生时被确定，所有父母的血清都是 在怀孕初期绘制并储存起来以备将来使用 研究。已经从两名患者的记录中确认了115例 大型纵向研究：儿童健康与发展 研究(CHDS)和合作围产期项目(CPP)， 分别有20,000和50,000名新生儿出生。每个三个控件 将从相同的人群中选择病例并进行匹配 父母的年龄和种族。父母的血清将会是 做了甲状腺抗体检测。 如果这一关联得到证实，它可能会有重要的公众 对健康的影响，因为目前还没有已知的风险 年龄以外的因素用于确定有风险的母亲 三体出生。虽然DS的发病率是10到100倍 在35至45岁的女性中，DS的大多数是 年轻母亲所生的孩子，对她们来说，作为一个群体，羊膜穿刺术 不会具有成本效益或风险效益。甲状腺抗体检测 价格低廉，对母子俩没有风险。母亲们 然后可以通过其他方法进行检测，例如 羊膜穿刺术。这项研究设计提供了独特的机会 以最低的成本测试这个重要的假设，因为 所需的记录和血样已经可以用于分析。

There is a body of epidemiologic evidence that has associated the birth of children with Down's syndrome or with other trisomies with the presence of thyroid antibodies in the serum of those children's parents. Cases for such studies were selected from children or adults with the syndromes who had survived the earliest years of life. If thyroid antibodies are a risk factor for chromosomal non-disjunction, then those antibodies should be present in a parent at the time of conception; otherwise the association could be due to selection bias for survivors whose altered immune system could be protective. We will test the hypothesis of an association of thyroid antibodies with trisomy births in a case-control study in which all cases and controls were ascertained at birth and all parental sera were drawn at the beginning of the pregnancy and stored for future research. 115 cases have been identified from the records of two large longitudinal studies, the Child Health and Development Study (CHDS) and the Collaborative Perinatal Project (CPP), with some 20,000 and 50,000 births respectively. Three controls per case will be selected from the same populations and matched for age and race of the mother and the father. Parental sera will be tested for thyroid antibodies. If this association is verified, it could have important public health implications because, at this time, there are no known risk factors other than age for the identification of mothers at risk of a trisomy birth. Although the incidence of DS is 10 to 100 times greater in women 35 to 45 years of age, the majority of DS are born to younger mothers for whom, as a group, amniocentesis would not be cost or risk effective. A test for thyroid antibodies is inexpensive and without risk to the mother-child pair. Mothers who were positive could then be tested by other means such as amniocentesis. This study design offers the unique opportunity to test this important hypothesis at a minimum of cost because the needed records and bloods are already available for analysis.