Abstract: Objective To investigate the risk factors ot HCMV reactivate infection in p regnancy and the influence to fetus.Methods To collect 351 sera samples of pregnant women,245 pairs of sera samples of puerpera and their infants to detect HCMV-IgM;inquire the age,the number of pregnancy and delivery as well as abortion history in order to see the influence on the infants.Results These factors may relate to HCMV reactivation,among them the number of pregnancy is the risk factor.HCMV reactivation affect fetus development,result in growth lagging,lower body weight of the new -born and the detection of HCMV particles and specific inclusion body in several organs.In the early stage of pregnancy cease the growth of fetus and cause abortion.Conclusion To reduce the number of pregnancy is eugenic,avoiding HCMV reactivate infection in the early stage of pregnancy can reduce the accurance of abortion and malformation.