出生缺陷(birth defects)是指出生前已经存在(在出生前或出生后数年内可以发现)的结构或功能异常,其产生原因包括遗传、环境以及两者的共同作用[1]。出生缺陷包括先天畸形(即胎儿的形态结构异常),也包括功能、代谢、行为异常,如代谢性疾病,先天性脑瘫等等。除此之外,低出生体重,死胎,流产等也被归入出生缺陷的范围内。出生缺陷主要有两大原因:一是遗传因素;二是环境因素;而大多数是遗传因素和环 Birth defects refer to the structural or functional abnormalities that existed before birth (can be found before birth or within a few years after birth) due to genetics, environment, and the combined effects of both [1]. Birth defects include congenital malformations (ie, morphological abnormalities in the fetus) as well as functional, metabolic and behavioral abnormalities such as metabolic diseases, congenital cerebral palsy and the like. In addition, low birth weight, stillbirth, abortion and so on are also classified as birth defects. There are two main causes of birth defects: First, genetic factors; the second is environmental factors; most of them are genetic factors and the ring