BIOLOGICAL EFFECTS OF DELAYED CHILDBEARING

30岁或35岁的妇女中头胎生育率显著增加， 在美国，从1975年到1986年， 每年69,000到230,000人。 关于是否存在 推迟分娩的产妇出现不良分娩结果的风险增加。 还有一个问题是，报告的不良反应风险是否会增加 出生结果是由于其他因素的混杂。 本研究是 使用基于人口的瑞典数据集， 1983年至1987年，除人口特征外， 医疗和妊娠并发症的信息，病史 不孕不育生育史以及吸烟 这是一个独特 数据集，我们不知道任何可比的人口为基础的 在美国的信息。 已出版三部手稿 从这项研究中。 这个项目已经完成。

There has been a marked increase in first births among women age 30 or more in the U.S. and the numbers have increased from 1975 to 1986 from 69,000 to 230,000 per year. There is a controversy as to whether there is an increased risk of adverse birth outcome among delayed childbearers. There is also a question whether the reported increase risk in adverse birth outcome is due to confounding by other factors. This research is using a population based Swedish data set of more than 500,000 births from 1983 to 1987, which in addition to demographic characteristics includes information on medical and pregnancy complications, history of infertility, reproductive history, as well as smoking. This is a unique data set and we are not aware of any comparable population based information in the United States. Three manuscripts have been published from this study. This project is completed.