Objective: Using nested polymerase chain reaction (PCR) to detect Intrauterine transmission of human cytomegalovirus (HCMV).
Methods: Ninety one cases of pregnant women were devided into three groups according to their gestational stages. In the first and second trimesters, they terminated pregnancy voluntarily. HCMV-DNA in maternal and cord blood as well as placenta were detected respectively by nested PCR.
Results: In the first trimester, 20 out of 30 cases were infected, Intrauterine transmission occured in 8 of the 20 infected mothers (HCMV-DNA were found in the chorionic villus). In the second trimester, 21 out of 30 cases were infected, 7 of them transmitted HCMV to their fetus through placenta. In this term, the placenta infection rate is 40% (12/30). In the third trimester, 23 out of 31 cases women infected HCMV, 18 of them transmitted HCMV to their fetus through placenta, the placenta infection rate is 66.67% (20/30). The congenital infection rate is 58.06% (18/31), much higher than the reported levels marked by cord sera IgM and (or) infants viremia.
Conclusions: HCMV transmitted from mother to infant mainly through placenta. Nested PCR provides a valuable method that can detected virus infection not limited by virus reproduction state and human immuno-reaction ability.