Breastfeeding Longer Helps Lower Mother-to-Infant HIV Risk

A new study regarding mothers who are HIV positive and fed their babies exclusively with breast milk in sub-Saharan Africa show that during the first four months of life, they had the lowest risk of transmitting the virus to their babies through the milk.

Researchers at Columbia University's Mailman School of Public Health said that there is approximately a 10 to 15 percent chance of transmitting the virus to their babies through breast milk. However, due to the rampant infectious disease in sub-Saharan Africa, breastfeeding is essential to keep infants healthy. It helps in both developing their immune system and fighting off infections.

To determine if early weaning could reduce transmission and infant mortality, Louise Kuhn, PhD, professor of Epidemiology at Columbia University's Mailman School of Public Health and colleagues looked at 950 HIV-infected women in Zambia. The women were told to breastfeed their infants from birth to at least four months. At the four month mark, half the women were encouraged to stop breastfeeding, while the others were encouraged to continue. Breast milk was collected throughout the study and regularly tested for HIV-transmission.

Those that stopped breastfeeding at a fourth month period at higher rates of HIV concentrations in their breast milk, with 77 percent having detectable concentrations. Of the women who continued to breastfeed exclusively at four and a half months, only 39.5 percent had a detectable concentration of the virus in their breast milk. Yet, when the two groups were compared just two weeks earlier than four months, their concentrations showed little to no difference.

"Our results have profound implications for prevent of mother to-child HIV transmission programs in settings where breast-feeding is necessary to protect infant and maternal health," wrote Dr. Kuhn, who is affiliated with the Gertrude H. Sergievsky Center at Columbia University Medical Center. 

"Our data demonstrates that early and abrupt weaning carries significant risks for infants."

The findings are online in the journal Science Translational Medicine.