True about HIV in pregnancy -

Mother to infant transmission is the major cause of pediatric AIDS. Infected mothers can transmit the infection to their offspring by three routes. i) In utero by transplacental spread ii)During delivery through an infected birth canal iii) After birth by ingestion of breast milk. Of these, transmission during birth (intrapartum) and in the immediate period thereafter (peripartum) is considered to be the most common mode. The reported transmission rate varies from 7% to 49%. Higher risk of transmission is associated with high maternal viral load and low CD4+ T-cell count as well as chorioamnionitis. Currently, with antiretroviral therapy given to infected pregnant women, the mother to child transmission has been reduced to very low levels. Zidovudine alone or in combination with lamivudine given to mother during the last few weeks of pregnancy or even only during labour and delivery and to the infant for a week or less reduces the transmission by 50%. Single dose nevirapine is also an effective prophylactic antiretroviral regimen. It is of particular relevance to low to mid income nations because of the low cost. There is a significant decrease in the risk of HIV transmission with an elective cesarean. LSCS reduces the risk because during this procedure the intrapartum period which accounts for a significant proportion of transmission is by-passed. Pregnancy does not predispose to HIV infection.