PI Perspective #24

April 1998     View PDF

AZT and Mother to Child Transmission

The reduction in HIV transmission from mother-to-infant with the use of anti-HIV drugs has been a remarkable success story. However, it has not been a reality for many nations where the complexity of the therapy regimen, along with poor access to the necessary drugs, inadequate prenatal care, wide scale malnutrition and the potential for transmission through necessary breast feeding, has blocked the ability to share in this major advance. Results from a new study in Thailand show the success of a simplified regimen of AZT which reduced by 51% the mother-to-child transmission among women who are not breast feeding (from 18.6% without AZT to 9.2% with AZT). In this study, women were given 300mg. AZT twice a day orally starting approximately 26 weeks after conception through birth. Unlike the standard U.S. regimen, the babies were not given AZT after birth, nor were the mothers given AZT intravenously during labor.

This greatly simplified regimen offers a more viable possibility for women in developing countries, even if it is slightly less efficacious (the U.S. regimen produced a 66% drop in transmission, versus 51% for the simplified regimen.) This simplified AZT regimen will be less costly, potentially allowing many developing nations to implement a useful campaign to reduce mother-to-child transmission of HIV. Further research will need to be done to determine the effectiveness for women who are breast feeding and whether still simpler regimens might be found for women who do not access care until delivery.