Approximately 20 percent of infants of HIV-infected mothers are infected before or during delivery. HIV can also be transmitted through breastfeeding. If all HIV-infected mothers breastfeed, an additional 14 percent of their infants would be infected through breastfeeding. It might seem logical to advise a mother with HIV not to breastfeed. If a mother knows she is infected, if breastmilk substitutes are affordable and can be fed safely, and if adequate health care is available and affordable, then the infant's chances of survival are greater if fed artificially.
Wet nursing is another alternative if a suitable uninfected woman is available.
Unfortunately, alternatives to breastfeeding are often neither affordable nor safe. In the 50 poorest developing countries, infant mortality averages over 100 deaths per thousand live births. Artificial feeding roughly triples the risk of infant death in such environments, where most infants deaths are due to infectious diseases such as diarrhea and pneumonia, where hygiene and sanitation are often poor, and where access to adequate health care is limited. In these conditions, breastfeeding may be the safest feeding option even when the mother is HIV-positive. Many experts believe that the safest way to breastfeed in the first six months is to do so exclusively, without adding any other foods or fluids to the infant's diet.