An HIV positive patient is pregnant. During which of the following stage is HIV transmission maximum?

Majority of HIV transmission occur during labour (40-80%). Perinatal transmission of HIV: Veical transmission of HIV to the neonate is about 14 - 25%. Transmission of HIV 2 is less frequent (1-4%) than HIV 1(14-35%). Veical transmission of HIV is more in cases with preterm bih and with prolonged membrane rupture. Risk of veical transmission is directly related to maternal viral load and inversely to maternal immune status. Maternal anti retro viral therapy reduces the risk of veical transmission by 70%. Breast feeding increases HIV 1 transmission by 14%. Ref: Textbook of Obstetrics By D.C Dutta, 6th edn, page 300.