Study author Dr. Heather Watts of the Eunice Kennedy Shriver National Institute of Child Health and Human Development said the rate of mother-to-child HIV transmission around the time of delivery was 2.2 percent among infants who received the standard drug zidovudine combined with nevirapine, compared with 4.8 percent among infants treated with zidovudine alone.
The study, which involved 1,600 infants, found a reduced rate of transmission -- 2.4 percent -- among infants treated with a three-drug combination: zidovudine, nelfinavir and lamivudine.
However, infants given the two-drug combination were less likely than were those on the three drug regimen to have neutropenia -- a blood disorder consisting of low levels of neutrophils, a type of infection-fighting white blood cells.
"Pregnant women who don't know they have HIV or those who don't come in for prenatal care may not get the early treatment needed to keep the virus from being passed on to the baby," Watts said in a statement. "Our findings show that even in these situations, many, many infant cases of HIV can be prevented with the two drug combination treatment."
The findings were published in the New England Journal of Medicine.