Although there are no full controlled studies of d4T (stavudine, Zerit) in pregnancy, a recent study has reported that d4T in conjunction with other antiretrovirals was well tolerated in ten pregnant women[1]. However, because of the small size of this study, and the potential low risk of blood disorders, congenital abnormalities and miscarriage, d4T should be administered to pregnant women with caution[2][3].

Pregnant women taking ddI and d4T together may be at increased risk of the life-threatening condition lactic acidosis. This was the subject of a warning by the United States Food and Drug Administration and Bristol-Myers Squibb, d4T’s manufacturer, in January 2001, following three reported deaths in pregnant women taking these two drugs.