Increased risk of severe infant anemia after exposure to maternal HAART, Botswana.

Background: Maternal highly-active antiretroviral therapy (HAART) reduces mother-to-child HIV transmission but may increase the risk for infant anemia.
Methods: The incidence of first severe anemia (grade 3 or 4, Division of AIDS 2004 Toxicity Table) was assessed among HIV-uninfected infants in the Mashi and Mma Bana mother-to-child HIV transmission prevention trials in Botswana. Severe anemia rates were compared between 3 groups: infants exposed to maternal HAART in utero and during breastfeeding (BF) and 1 month of postnatal zidovudine (ZDV) (HAART-BF); infants exposed to maternal ZDV in utero, 6 months of postnatal ZDV, and BF (ZDV-BF); and infants exposed to maternal ZDV in utero, 1 month of postnatal ZDV, and formula-feeding (ZDV-FF).
Results: A total of 1719 infants were analyzed-691 HAART-BF, 503 ZDV-BF, and 525 ZDV-FF. Severe anemia was detected in 118 infants (7.4%). By 6 months, 12.5% of HAART-BF infants experienced severe anemia, compared with 5.3% of ZDV-BF (P < 0.001) and 2.5% of ZDV-FF infants (P < 0.001). In adjusted analysis, HAART-BF infants were at greater risk of severe anemia than ZDV-BF or ZDV-FF infants (adjusted odds ratios 2.6 and 5.8, respectively; P < 0.001). Most anemias were asymptomatic and improved with iron/multivitamin supplementation and cessation of ZDV exposure. However, 11 infants (0.6% of all infants) required transfusion for symptomatic anemia. Microcytosis and hypochromia were common among infants with severe anemia.
Conclusions: Exposure to maternal HAART starting in utero was associated with severe infant anemia. Confirmation of this finding and possible strategies to mitigate hematologic toxicity warrant further study.