Intrapartum HIV transmission rates remain as high as 12 to 26%, but a new study suggests combination ART reduces maternal-fetal transmission.
The study compared the efficacy of three different antiretroviral drug regimens for prevention of intrapartum HIV-1 transmission in infants whose mothers did not receive ART during pregnancy. The study, which only included infants who were formula-fed, randomly assigned newborn infants (<48 hours old) to one of three ART regimens which were as follows: 1) zidovudine alone for 6 weeks 2) zidovudine regimen plus three doses of nevirapine 3) zidovudine regimen plus nelfinavir and lamivudine for 2 weeks.. Infants were tested for HIV at birth and then subsequently at 10 to 14 days, 4-6 weeks, 3 months, and lastly at 6 months of age. If the infants were confirmed to be HIV positive at any of these points (including birth), the prophylaxis ART regimen was discontinued and they were initiated on treatment ART. It should be noted that infants found to be HIV positive at birth were excluded from statistical analysis. The primary study end point was intrapartum HIV-1 transmission at 3 months of age.
2- and 3-drug ART reduces intrapartum HIV infection
While early identification of positive HIV status in the prenatal period and timely initiation of ART for the mother remains the most effective strategy to prevent intrapartum HIV infection, this study offers support for a second window of opportunity. Even in situations where mothers are identified as being HIV positive in the brief intrapartum period, the use of a two or three-drug ART regimen offers more protection to the infant from HIV transmission than the current standard single drug regimen. Given these findings, combination ART regimens are likely to become standard of care for post exposure prophylaxis in this population of infants.
Nielsen-Saines, Karin etal. Three Postpartum Antiretroviral Regimens to Prevent Intrapartum HIV infection. New England Journal of Medicine June 2012; 366:2368-2379.
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