Similar to a previous study(12), it is noticed that the known case of HIV infection before current pregnancy and viral load < 400 copies/ml were found as a protective factor of anemia in the present study. Almost all the known cases of HIV infection before current pregnancy in the present study had viral load < 400 copies/ml after highly active antiretroviral therapy (HAART) and patients intended to have pregnancy. Any direct cause of anemia from HIV infection in this group of patients, such as a consequence of inflammation, was eliminated. Regarding to the association between AZT-based HAART regimens during ANC for viral suppression and anemia, neither the present study nor the previous studies(12) found this association.