Although there have been no formal studies of ddI (didanosine, Videx / VidexEC) in human pregnancy, results from animal studies have revealed no evidence of potential harm to the foetus. As animal studies do not always predict the effect of drugs in humans, ddI should be used with caution in pregnant women.

Pregnant women taking ddI and d4T (stavudine, Zerit) may be at an increased risk of the life-threatening condition lactic acidosis. This was the subject of a warning issued by the United States Food and Drug Administration and Bristol-Myers Squibb in January 2001.