HIV and pregnancy

Abstract
Timing of and factors affecting mother to child transmission Perinatal transmission of HIV can occur in utero, during labour and delivery, or postnatally through breastfeeding.1w1 Most transmission occurs during the intrapartum period.1 Transmission will vary from less than 2% in the developed world (with its access to antiretroviral therapy, caesarean section, and formula milk) to more than 30% in the developing world (where access to therapy is limited and breastfeeding is prolonged). w2 Observational studies have shown that the risk of perinatal transmission is affected by maternal stage of disease; duration of rupture of membranes; increased genital secretion of HIV associated with sexually transmitted infections such as herpes simplex virus; and other factors such as prematurity. Large randomised controlled studies have shown that mother to child transmission can be reduced by the use of antiretroviral therapy, elective caesarean section, and exclusive formula feeding.2