Absence of maternal-fetal transmission of human immunodeficiency virus type 1 to second-trimester fetuses

Objective: The aim of this study was to evaluate the contribution of in utero infection to the vertical transmission of human immunodeficiency virus type 1 during the second trimester. Study Design: We examined fetal tissues from 21 second-trimester prostaglandin-induced abortions among human immunodeficiency virus type 1–infected women and compared the fetal vertical transmission rates with those among children born to human immunodeficiency virus–seropositive women. The presence of human immunodeficiency virus type 1 nucleic acid sequences was investigated with two different highly sensitive polymerase chain reaction techniques in tissue samples from the fetal thymus, lung, and brain. Results: No human immunodeficiency virus type 1 deoxyribonucleic acid was detected in any of the samples. Conclusion: The absence of human immunodeficiency virus type 1 in all fetuses in our study is compatible with a low rate of maternal-fetal transmission during the second trimester of pregnancy. (Am J Obstet Gynecol 2000;183:638-42.)