Cohort of 160 HIV-infected women, approached at > 28 weeks gestation and initiated on routine HAART for the purposes of PMTCT.

A cohort of 160 women will be enrolled from the control clinics, from 28 weeks gestation onward. At these sites, the antenatal zidovudine will be offered, with provision of single-dose nevirapine for self-administration in labor. This practice is in accordance with the current standard of care recommended by the Zambian National Guidelines for PMTCT.

Women who are identified as HIV-infected will be offered routine combination antiretroviral prophylaxis starting at 28 weeks gestation (timing consistent with Zambian national guidelines for short-course ZDV). The first-line combination provided to pregnant women will be standardized following consultation with the Ministry of Health, but will likely include ZDV, lamivudine (3TC) and either NVP or lopinavir / ritonavir. In women who with moderate to severe anemia, ZDV is substituted with stavudine (d4T). In accordance with the Zambian national guidelines, any patients who are started on NVP will begin with a once daily dose for two weeks before increasing to the regular twice daily schedule