ART administered during breast-feeding may reduce mother-to-child transmission

All regimens of antiretroviral therapy administered from pregnancy through 6 months of postpartum breast-feeding may have yielded a 1.1% rate of mother-to-child transmission of HIV, according to recently released study results.

Researchers from the Harvard School of Public Health conducted a trial among 730 pregnant women in Botswana, Africa. The trial was part of the Mma Bana Study and was among the first of its kind to compare ART regimens used in pregnancy or breast-feeding. Outcome measures included comparisons of nucleoside reverse transcriptase inhibitor (NRTI) and protease inhibitor (PI) groups, with an observational group receiving a nevirapine-based regimen. The aim was to determine the proportion of women with plasma HIV RNA levels less than 400 copies/mL at delivery and through breast-feeding at 1, 3 and 6 months or at all visits before weaning and at the time of ART discontinuation.

The final analysis included 560 pregnant women with HIV who had CD4 cell counts of at least 200 cells/mL. There were 285 participants randomly assigned coformulated abacavir, zidovudine and lamivudine (NRTI group) and 275 women assigned lopinavir-ritonavir plus zidovudine-lamivudine (PI group). There were 170 women in an observational group with CD4 counts less than 200 cells/mL who received nevirapine plus zidovudine-lamivudine. Treatment began at 26 to 34 weeks’ gestation. Infants were administered single-dose nevirapine and 4 weeks of zidovudine.

In the NRTI group, three women withdrew from the study, eight had stillborn infants and 274 had live-born infants. Ten women decided not to breast-feed and 264 initiated breast-feeding while receiving ART.

In the PI group, there was one withdrawal, five still-born infants and 269 live-born infants. Six women decided not to breast-feed and 263 women initiated breast-feeding while receiving ART.

In the observational group, three women withdrew from the study, one died, 10 had still-born infants and 156 had live-born infants. Six women chose not to breast-feed and 150 women chose to initiate breast-feeding.

Virologic suppression rates at delivery (less than 400 copies/mL) were 96% in the NRTI group, 93% in the PI group and 94% in the observational group. Throughout breast-feeding, the rates were 92% in the NRTI group, 93% in the PI group and 95% in the observational group.

During HIV testing at 6 months, eight of the 709 infants (1.1%; 95% CI, 0.5-2.2) were infected. Six had been infected in utero and two were infected during breast-feeding. Among infants infected in utero, four were in the NRTI group, one was in the PI group and one was in the observational group. Both babies infected during breast-feeding were in the NRTI group.

Adverse event profiles indicated that 2% of women in the NRTI group, 2% of women in the PI group and 11% of women in the observational group experienced treatment-limiting events.

Max Essex, PhD, Mary Woodard Lasker Professor of Health Sciences and chair of the Harvard School of Public Health and AIDS Initiative, was involved in the research. “Until now, HIV-infected mothers in Africa were faced with a choice between breast-feeding and a high risk of infecting their children with HIV, or using formula and risking high infant morbidity and mortality from other diseases associated with not breast-feeding,” he said in a press release. “The study provides a more satisfactory solution.”

Shapiro RL. N Engl J Med. 2010;362:2282-2294.