Xu Y J
Zhonghua Liu Xing Bing Xue Za Zhi. 1989 Aug;10(4):223-6.
A case-control study was conducted on birth defects of newborns using L&R disordent pair-matching in Tangshan between 1983 and 1987. The results showed that upper respiratory tract infection among the newborns' mothers during the first 12 weeks pregnancy and a history of newborns' parents who exposed to harmful environment were the main risks of birth defects. There were no evidences that upper respiratory tract infection among the newborns' mothers after the first 12 weeks' pregnancy and taking medicine during pregnancy had obvious association with birth defects.
1983年至1987年期间，在唐山采用L&R失调配对法对新生儿出生缺陷进行了病例对照研究。结果表明，新生儿母亲在怀孕前12周内的上呼吸道感染以及新生儿父母有接触有害环境的历史是出生缺陷的主要风险因素。没有证据表明新生儿母亲在怀孕12周后发生的上呼吸道感染以及孕期服药与出生缺陷有明显关联。
