AZT Curbs Spread of AIDS Virus During Pregnancy, Study Shows

BOSTON —  AZT drug treatments can limit the spread of the AIDS virus from a mother to her newborn baby, but the reason it works remains unclear, according to a study in today’s New England Journal of Medicine.

The study led a team of doctors to recommend AZT treatment for any pregnant woman with the AIDS virus, regardless of how much virus material can be detected in the blood.

Doctors do not understand how the AIDS virus is passed to a baby. Conventional wisdom holds that 50% to 70% of all AIDS babies acquire the virus around the time of birth, but it is unclear whether a child becomes infected in the womb or during delivery.

A group of researchers led by Dr. Rhoda Sperling of the Mount Sinai School of Medicine in New York City decided to see if virus levels in the mother influenced the chances of her infant being infected with the AIDS virus. They found that the higher the levels of the virus in a mother’s blood, the greater the likelihood the disease would be passed on to the baby. But there were plenty of exceptions to that rule.

The group also expanded on work, reported two years ago, showing that AZT cuts by two-thirds the infection rate among newborns whose mothers carry the AIDS virus.