Low birth weight associated with HAART in pregnancy in Zambia

Investigations of the risk of preterm delivery (PTD) and low birth weight <2.5kg (LBW) associated with antiretroviral use (particularly protease inhibitors) in pregnancy have yielded conflicting results both in resource limited and well-resourced settings.

Results were presented from a Zambian study authored by Michael Silverman and colleagues looking at the association with lopinavir/r (LPV/r). [1] Its name, The Aluvia study, perhaps reveals, that it was conducted in association with Abbott, the innovator manufacturer of the drug.

This was a prospective study of LPV/r plus AZT and 3TC taken twice daily at the standard dose started between 14 and 30 weeks of gestation in 280 Zambian women who planned to breastfeed.

The investigators compared these results with historical data from the Zambia Exclusive Breastfeeding Study (ZEBS), conducted at the same location but at a time when HAART was unavailable. Almost all (99.3%) the women in ZEBS received single dose nevirapine (NVP) prophylaxis.

At the time of the analysis, 200 women had delivered 206 live infants and six week HIV DNA PCR results were available for 158 infants, out of which two (1.3%) were diagnosed with HIV.

The combined rate of HIV-infection at six weeks and mortality at three months post partum was 8/153 (5.2%) compared to 144/958 (5.2%) in ZEBS, p<0.001.

They reported a mean birth weight for the Aluvia cohort of 2.9kg (SD 0.5) with a LBW incidence of 35/206 (16.9%) compared to 105/937 (11.2%) in ZEBS, p=0.02.

There were no significant differences in maternal risk factors for LBW (CD4 <350 cells/mm3, anaemia, multiple birth, febrile illness). When they compared the women with LBW and non-LBW infants in the Aluvia group the investigators reported no differences in potential risk factors (maternal CD4 count, hypertension, other infections, anaemia, diabetes, malaria) apart from a higher incidence of multiple births in the LBW group (4/33
vs 1/167, p<0.01).

They concluded that the LPV/r regimen does appear to be associated with LBW in this cohort, but that (unsurprisingly) the transmission rate is lower than that with single dose NVP.

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Ref: Silverman MS et al. Low birthweight (LBW) associated with antepartum HAART in Zambia. 50th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), 1215 September 2010, Boston. Poster abstract H-1662.