451168 先天畸形的病因分析朱煜英等中国农村医学(2):47～48,1985 非遗传因素:①生物因素;主要是病毒,孕妇患某种病毒感染,经胎盘传至胎儿,造成宫内胎儿感染,干扰一些器官组织的正常形成而致畸。孕期第一个月感染风疹病毒,致畸机率是50％,第二个月为30％,第3个月为20％。 451168 etiology of congenital malformations Zhu Yuying other Chinese rural medical (2): 47 ~ 48, 1985 Non-genetic factors: ① biological factors; mainly viruses, pregnant women suffering from a virus infection, transmitted to the fetus through the placenta, resulting in intrauterine fetal infection , Interfere with the normal formation of some organs and teratogenic. Rubella is infected in the first month of pregnancy, with a teratogenic rate of 50%, a second month of 30% and a third of 20%.