Evidence for infection of the human embryo with adeno-associated virus in pregnancy

Previous reports have demonstrated the presence of DNA of the human helper virus-dependent adeno-associated parvovirus (AAV) in uterine tissue and cur ettage material from early miscarriage. To examine infection of embryonic t issue during pregnancy, amnion fluids mere analysed for the presence of AAV . Using polymerase chain reaction, AAV DNA was detected in 64 out of 238 DN A samples extracted from amnion cells. DNA of helper viruses were found in 12% (papillomavirus) and 18% (cytomegalovirus) of the samples (double infec tions with A;IV in eight and nine cases, respectively). Furthermore, infect ious AAV virions were found in 13 out of 43 AAV DNA-containing samples. In mothers with AAV DNA-positive amnion fluids, premature amniorrhexis and pre mature labour occurred significantly more frequently (P < 0.001). Using an immunofluorescence assay, 24% of newborn sera (unrelated to the amnion flui d samples) were found to contain IgM antibodies to AAV, in most cases paral leled by IgM antibodies in the mother's sera. The data demonstrate that AAV infection can occur ill utero at early and at late stages of pregnancy. Th e observed complications at delivery should encourage studies to clarify po ssible pathological consequences of AAV infection in pregnancy and a possib le latent infection of the fetus.