Antiretroviral use in pregnancy and the risk of an adverse outcome

Polly Clayden, HIV i-Base

Use of antiretroviral therapy during pregnancy for HIV-1 infected women, for benefit to maternal health and to reduce mother to child transmission (MTCT), is now widely recommended. However, there are limited data on complications associated with treatment during pregnancy, and some studies have suggested that combination therapy may increase the risk of premature birth.

A paper published in the June 13th issue of New England Journal of Medicine examined data from a group of women (and their infants) enrolled in seven studies who gave birth during the period 1990 to 1998, to evaluate the risk of premature birth and other adverse outcomes associated with antiretroviral use.

Of the 2123 women using antiretrovirals, 1590 received monotherapy, 396 combination therapy without protease inhibitors and 137 combination therapy including protease inhibitors. A comparitor group of 1143 women did not receive antiretrovirals.

The rate of very premature delivery, defined as delivery at less than 32 weeks, was not significantly different between the groups of treated and untreated women (2% and 1% respectively) unadjusted for CD4 cell count, use or non-use of tobacco, alcohol and street drugs. In addition unadjusted rates among infants of low and very low birth rate, abnormal Apgar scores and stillbirths did not differ between the two groups. Unadjusted rates of premature birth however, defined as delivery at less than 37 weeks, were slightly lower among women treated with antiretrovirals (16% and 17%). Adjusted rates of adverse outcomes also remained similar in both groups.

The authors also found that low maternal viral load and the use of combination therapy during pregnancy are associated with rates of vertical transmission of 2% or less.

Overall the investigators concluded that their ”…data provide reassurance that the risks of adverse outcomes of pregnancy that are attributable to antiretroviral therapy are low and likely to be outweighed by the recognised benefits of such therapy during pregnancy.”


Tuomala RE, Shapiro DE, Mofenson LM et al. Antiretroviral therapy during pregnancy and the risk of adverse outcome. N Engl Med, Vol.346. June 13. 2002

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