Common occurrence of anaemia at the end of pregnancy following exposure to zidovudine-free regimens.

Objective: Although zidovudine-free regimens are increasingly used in pregnancy, their haematological effects in mothers and newborns are incompletely defined.

Methods: The haematological profiles of 119 HIV-infected women and their neonates with highly active antiretroviral regimens (HAART) in pregnancy including or not zidovudine (ZDV) were investigated. Three groups were compared: 1) women who started ZDV-lamivudine (3TC)-based HAART during pregnancy (ZDVs, n = 60); 2) women on ZDV-3TC-based HAART from conception (ZDVc, n = 18); 3) women on ZDV-free HAART from conception (ZDVf, n = 41).

Results: At the beginning of pregnancy, haemoglobin levels were similar in the three groups. By week 36 compared to baseline, haemoglobin levels had a significantly greater decrease in ZDVf women compared to ZDVs women (ZDVf: -2.03 g/dl; ZDVs: -1.36 g/dl, p = 0.036). A similar trend was observed for occurrence of maternal anaemia at 36 weeks. Newborns with no prenatal ZDV exposure had significantly higher haemoglobin levels at birth (ZDVf: 16.1 ± 1.4 g/dl, ZDVs: 14.3 ± 2.0 g/dl; ZDVc: 14.6 ± 2.4 g/dl, p = 0.044 and 0.003, respectively).

Conclusions: Half of ZDV-unexposed mothers had anaemia at the end of pregnancy, but their neonates had normal haemoglobin levels. ZDV initiation was associated with a lower occurrence of maternal anaemia during the third trimester and decreased haemoglobin levels in the newborns. We hypothesize that foetal iron requirements could represent a major determinant of maternal anaemia at the end of pregnancy.