HIV transmission tenfold higher when mom combines nursing and formula feeding

HIV-infected women who choose to breastfeed are less likely to transmit the virus to their infant if they avoid mixed feedings with formula and solids and exclusively breastfeed instead. The study of South African women is published in the March 31 issue of The Lancet.

Nigel C. Rollins, MD, of the University of KwaZulu-Natal in Congella, South Africa, and colleagues conducted a study of 2,722 HIV-infected and uninfected pregnant women from nine antenatal clinics. The mothers supplied data on infant feeding every week and the babies underwent monthly blood tests for HIV.

There were 1,372 infants born to HIV-infected mothers, of whom 1,132 (83%) were exclusively breastfed from birth and for a median 159 days. By the age of 6 weeks, 14.1% of the infants were infected with HIV-1, and 19.5% were infected by age 6 months. However, breastfed babies who received solids and who were given mixed feeding with formula and breast milk were at significantly higher risk of infection (adjusted hazard ratios, 10.87 and 1.82, respectively). At 3 months, the cumulative mortality rate for exclusively breastfed infants was 6.1%, versus 15.1% for those given mixed nutrition.

Coovadia HM, Rollins NC , Bland RM. Mother-to-child transmission of HIV-1 infection during exclusive breastfeeding in the first 6 months of life: an intervention cohort study. Lancet. 2007;369:1107-1116.