One of HIV’s cruelest ironies is that it seeds the body’s most intimate, regenerative acts with disease and danger. So it is with breast-feeding—an infant’s ideal form of nourishment, an important source of disease-fighting antibodies and a deep bonding experience. Studies have found that breast-feeding can dramatically increase the risk of transmission (with the highest rates during the first four months) compared with bottle-feeding. As a result, health agencies in developed countries recommend that mothers substitute infant formula. (No data support the idea that women with undetectable viral loads due to combination therapy can safely breast-feed.)

But for women in poor nations, the World Health Organization recommends only “informed choice” because they face a more complex, even agonizing decision: Many may lack access to both formula and to the clean water necessary to use it safely. Mixing powdered formula with contaminated water can increase the baby’s risk of death from diarrhea and dehydration. And breast milk may be the only nutritious food available to save the baby from starvation. Surprisingly, one study suggests that combined feeding regimens (breast milk plus formula and other foods) may put babies at higher risk of HIV transmission than breast-feeding alone. This may be because contaminated or hard-to-digest food can injure infants’ intestines, increasing the chances of infection.

A useful book that offers a careful and comprehensive analysis of these issues is Breastfeeding and HIV/AIDS, by Edith White (McFarland & Company; 800.253.2187), $39.95.