A new study conducted by researchers at Columbia University's Mailman School of Public Health suggests that the risk of transmitting HIV virus to babies is the lowest among HIV infected mothers who breast feed their babies exclusively for more than the first four months of life.
Women who stopped breast feeding earlier than four months had the highest concentrations of HIV in their breast milk, and those who continued to breastfeed, but not exclusively, had concentration levels in-between the two practices. The findings are online in the journal Science Translational Medicine. HIV-infected women typically have a 10% to 15% chance of transmitting the virus to their babies through breast milk. However, in sub-Saharan Africa where infectious diseases are rampant and often life-threatening, breastfeeding is essential for keeping infants healthy. Breast milk contains many important components that help developing immune systems fend off infectious diseases.
To test whether changes in breastfeeding routines affect levels of HIV in breast milk, Louise Kuhn, PhD, Mailman School professor of Epidemiology, and colleagues conducted a randomized clinical trial to examine the effectiveness of early weaning to reduce HIV transmission and infant mortality. Over 950 HIV-infected women in Zambia were recommended to breastfeed their babies starting at birth for at least four months. At four months, half of the women were encouraged to stop breastfeeding, while the other half was advised to continue. Breast milk was collected from all women at four and a half months. Throughout the study, infants were tested regularly for possible HIV transmission. The researchers found the highest concentrations of HIV in the breast milk of women who stopped breastfeeding at 4 months.