HIV tests on women in labor can protect infants, study says
CHICAGO -- Government research indicates a rapid HIV test can be used on women during childbirth, results that doctors hope will help reduce HIV infections in newborns.
Though HIV infection of newborns is not widespread in the United States, it is of great concern in Africa and other developing areas.
Interrupting the often excruciating yet exhilarating experience of childbirth to test and tell a woman she is infected may seem almost cruel -- but it gives doctors a good chance of preventing her baby from becoming infected, too, said study coauthor Dr. Mardge Cohen.
It takes about 20 minutes to get results from rapid tests compared with more than a day for conventional HIV testing. Testing during childbirth allows doctors to begin treating the mother during labor -- when most mother-to-infant infections occur -- and to start early preventive treatment in newborns.
"It is a very difficult time and a very special time, and to learn very bad news but to have the opportunity to do something about that" is worthwhile, said Cohen, an AIDS specialist at Chicago's John H. Stroger Jr. Hospital of Cook County. The research is to be reported in Wednesday's Journal of the American Medical Association.
The federal Centers for Disease Control and Prevention estimates that some 300 or so US infants are born each year infected with the virus that causes AIDS, despite recommendations for prenatal HIV testing and for use of AIDS drugs during pregnancy in infected women.
An estimated 700,000 children worldwide developed HIV infections last year, most in Africa and from mother-to-child transmission during childbirth or early infancy. The problem is especially acute in southern Africa, where about 1 in 5 pregnant women has HIV but is unaware of it and many do not see a doctor until giving birth.
Without drug treatment before birth for mothers and shortly thereafter for newborns, babies born to infected women have a 25 percent chance of becoming infected. With optimal treatment of the mother, the transmission rate drops to less than 2 percent, Cohen said.
The odds increase if the mother is not treated until she is in labor, but that is still better than no treatment at all.
In the study, HIV was diagnosed in three of 34 babies born to HIV-infected women who got tested and treated during labor, about 10 percent.
The study involved 5,744 previously untested women at 16 US hospitals who were asked to undergo rapid testing during labor. The vast majority -- 84 percent, or 4,849 women -- consented.
"They're in pain, they're having contractions, they have a lot else going on" but still agreed to be tested, Cohen said. "It's totally encouraging."
The rapid test used, Orasure Technologies' OraQuick test, involves a finger-prick blood test and was approved for US use in 2002.
It took an average of 66 minutes to test, get results, and explain them to the women -- plenty of time to begin treatment while labor was still progressing, Cohen said.
Treatment for HIV-exposed infants was generally AZT (zidovudine) syrup every six hours for six weeks; some also got a single dose of nevirapine, an inexpensive AIDS drug shown to help prevent mother-to-child transmission. Infected mothers also got AZT, and some received nevirapine, too.
The results could have the greatest public health benefits if they prompt practice changes in Africa, according to an editorial in the Journal of the American Medical Association by two Harvard physicians.
"The ability to screen women rapidly for HIV infections and offer antiretroviral therapy has the potential to prevent HIV transmission to hundreds of thousands of infants that otherwise might occur," Dr. Timothy Brewer and Dr. S. Jody Heymann wrote.
