HIV-infected mothers who breast-fed exclusively longer than the first four months after birth had less risk of transmitting the virus to their babies through their milk, researchers said.
To test whether breast-feeding routines affect the levels of HIV in breast milk, the researchers tested nearly 1,000 women and their infants in Lusaka, Zambia, over 24 months. The women were divided into two groups – one that weaned their babies abruptly after four months, and one in which the women continued to breast feed as long as they chose.
At 4 1/2 months, the HIV concentrations in breast milk were “substantially higher” in the group that weaned than in the group that continued to nurse their children. And among those who kept nursing, the HIV levels were higher among women who did not do so exclusively, the researchers wrote. And, they said, the results are conservative, because only 60.5% of the women who were to wean their children actually did so by 4 1/2 months.
“Our results have profound implications for prevention of mother-to child HIV transmission programs in settings where breast-feeding is necessary to protect infant and maternal health,” the researchers from Columbia University wrote. The results were published Wednesday online in the journal Science Translational Medicine.