During pregnancy HIV transmission occurs mostly during

Ans. is 'd' i.e. during labour HIV can be transmitted from an infected mother to the fetus during pregnancy, during delivery or by breastfeeding.HIV can be transmitted to the fetus as early as the first and second trimester of pregnancy.The transmission during birth (intrapartum) and the immediate period thereafter (peripartum) is considered to be the most common.In the absence of prophylactic antiretroviral therapy of the mother during pregnancy, labor and delivery and to the fetus following birth, the probability of transmission of HIV from mother to infant ranges from 15-25% in industrialized countries and 25-35% in developing countries.Higher risk of transmission is associated with high maternal viral load.Low CD4 count is also considered a risk factor.A prolonged interval between membrane rupture and delivery is another well documented risk factor for transmission.Other conditions that are potential risk factors but which have not been consistently demonstrated are:Presence of chorioamnionitis at deliverySTD's during pregnancyHard drug use during pregnancyCigarette smokingPreterm deliveryObstetrics procedures such as amniocentesis, amnioscopy fetal scalp electrodes, episiotomy.There is significant decrease in the risk of HIV transmission with elective cesarean.LSCS reduces the risk because during this procedure, the intrapartum period which accounts for significant proportion of transmission is by passed.