Most children acquire human immunodeficiency virus (HIV) infection vertically from an infected mother. Indirect evidence suggests that a substantial proportion of infection is acquired around the time of delivery, which suggests that this would be an appropriate time to intervene. If
intrapartum transmission of HIV occurs primarily through direct exposure of the infant to cell‐associated or free HIV in genital secretions or blood during passage through the birth canal, or by ascending infection, caesarean section performed prior to labour might reduce the risk of
transmission. There is insufficient evidence to justify routine caesarean section deliveries for HIV‐infected women, and a randomized clinical trial of mode of delivery has started in Europe.