Pregnant women who are infected with the AIDS-causing human immunodeficiency virus HIV may dramatically reduce the rate of transmission of the virus to their unborn infants if they receive routine obstetrical care and take the medication zidovudine AZT orally during their pregnancy, according to School of Medicine researchers.
The Yale findings, reported in the Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology, represent a different way of counseling, testing and treating pregnant women who are infected with HIV, according to Dr. Warren A. Andiman, professor of pediatrics at the medical school and an attending physician at Yale-New Haven Hospital YNHH.
From 1990 to 1993, a total of 267 infants were born to 245 HIV-infected mothers who were treated during their pregnancy with AZT at YNNH's high-risk obstetrical unit. The rate of HIV infection transmitted from the mothers to their babies was reduced from 19 percent to 5 percent, Dr. Andiman says. "In addition, medication was given neither to the mothers during labor, nor to the infants, and we still showed this reduction in transmission of HIV.
"Our study is one of a handful of U.S. studies that have begun to show this same phenomenon," notes Dr. Andiman. "The Yale study results are more robust because all of the data were collected at a single institution, where delivery of care was uniform -- Yale-New Haven Hospital." The hospital is affiliated with the School of Medicine.
"Our study provides further support for the effort to encourage widespread, perhaps universal education and counseling about HIV infection," Dr. Andiman concludes. "All women of child-bearing age need to be offered an opportunity to be tested for HIV. Those found to be infected should then be offered treatment with AZT."
Globally, the Yale research also offers implications in preventing the transmission of HIV from mothers to children, notes Dr. Andiman. This approach is especially significant for pregnant women in developing countries, where neither financial resources nor the technical sophistication exist to undertake a rigorous program of administering intravenous medications during labor and delivery, he says.
Pregnant women who are infected with HIV could routinely be offered therapy with the orally administered AZT to reduce both the amount of virus and the risk of vertical transmission, Dr. Andiman and his colleagues recommend in their article. "It is easier to administer oral rather than intravenous medication, thereby making it applicable to women who live in non-industrialized countries," write the researchers.
"The cost of preventing pediatric cases using oral AZT would be far less than the financial, emotional and social burden of caring for the large numbers of babies who otherwise would be born infected with HIV," the Yale team concludes. Oral AZT costs approximately $1.50 per pill, so five 100-milligram pills a day given to the mother would cost only $7.50 per day to prevent infection in a child -- compared with the tens of thousands of dollars to treat an HIV- infected infant for life, they say.
This research was supported, in part, by grants from the National Institute of Allergy and Infectious Diseases and the National Institute on Drug Abuse. Coauthors with Dr. Andiman are B. Joyce Simpson, a research nurse and administrative coordinator of the pediatric AIDS program in the department of nursing at YNHH, and Dr. Eugene D. Shapiro, professor of pediatrics and of epidemiology and public health at the medical school and an attending physician at YNHH.