Current issues in the prevention of mother-to-child transmission of HIV-1 infection

Worldwide every year approximately 750,000 children become infected with HIV, mostly through mother-to-child transmission (MTCT). Without specific interventions, the rate of MTCT is approximately 15-20%, with prolonged breastfeeding doubling the rate to 35-40%. Current approaches to intervention to reduce the risk of MTCT focus mainly on antiretroviral prophylaxis during pregnancy, labour and in the early neonatal period, but in some settings also on delivery procedures and avoidance of breastfeeding. To reduce the risk of breastfeeding transmission, shortening the breastfeeding period and/or encouraging exclusive breastfeeding has been suggested. MTCT rates of less than 2% are now reported from countries where antiretroviral prophylaxis, elective Caesarean section and refraining from breastfeeding can be applied, whilst in settings where refraining from breastfeeding is not feasible or safe and where elective Caesarean section is also not a safe option, peripartum antiretroviral therapy can halve the risk to levels of approximately 10% at 6 weeks, although further acquisition of infection through breastfeeding substantially increases the overall rate to 20% or more. In light of the high mortality in all children of HIV-infected women, programmes for prevention of MTCT should be monitored not only in terms of HIV transmission avoided but also in terms of child survival.