Chromosomal mosaicism in a pregnant woman treated with acyclovir for herpes simplex encephalitis

At 17th week of pregnancy, a 28-year-old woman was diagnosed as having herp es simplex: encephalitis and treated with intravenous acyclovir. Follow-up by the serial ultrasound examinations, intrauterine growth retardation (IUG R) was found. During the course of disease, cordocentesis was performed to evaluate the risk of the disease and the infant's chromosomal constitution. No herpes simplex virus infection on cord blood sample was observed; howev er, chromosomal analysis revealed: 46,XX/47,XX,+2/47,XX,+11/47,XX,+19/48,XX X,+11. After termination of pregnancy, the fetus was found as having ventri cular septum defect. The presence of the triploid cell lines mocaicism invo lving chromosome 2 and 19 were, confirmed by the analysis of fetal skin tis sues. No attributable finding to herpes simplex virus infection and acyclov ir treatment was found, and the presence of the triploid cell lines mocaici sm were appeared to be purely coincidental.