Preconceptional primary human cytomegalovirus infection and risk of congenital infection.

The risk of vertical transmission of human cytomegalovirus (HCMV) was investigated in 14 women who had primary HCMV infection 2-18 weeks before their last menstrual period during 2001-2004. One (8.3%) of 12 newborns examined at birth was found to be subclinically infected. Preconceptional primary HCMV infection has a transmission rate that is significantly higher than that observed in an unselected newborn population but significantly lower than that associated with maternal infection during pregnancy. Although a safe time interval between primary infection and initiation of pregnancy still needs to be defined, documented information can now be provided during counseling.