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| |  AAAS: Increase in DNA Mutations Seen in Offspring of Mothers Who Take Antiretrovirals in Pregnancy By Ed Susman Special to DG News BOSTON, MA -- February 20, 2002 -- Women who take antiretroviral therapy during pregnancy have been found to have babies who have twice as many DNA mutations as babies who were not exposed to the drugs in utero. Researchers analyzed DNA mutations in a cohort of 71 children who were exposed to zidovudine and lamivudine or a combination of the two drugs in utero and a control cohort of babies not exposed to the drugs. The findings were presented here Saturday at the annual meeting of the American Association for the Advancement of Science. "We really don’t know what this means as far as future problems such as the risk of cancer," said Vernon Walker, Ph.D., research scientist at the Lovelace Respiratory Research Institute, in Albuquerque, New Mexico. "However, it does indicate that warnings about future health problems that were promulgated by the Food and Drug Administration about use of these drugs in pregnant women were justified." So far, Dr. Walker said, there are no cases in which cancer related to the changes in drug use have been reported in the children. He noted that virtually all children are born with a few DNA mutations. In his study, the average number of mutations in 71 babies whose mothers took zidovudine (AZT) to prevent transmission of the HIV virus, there were an average of 2.6 mutations per million cells, about twice as many as seen in 68 children not exposed to the drug (1.3 per million cells). About 3 percent of the unexposed children had mutations that indicate an abnormal protein was created by the DNA damage, Dr. Walker. These types of mutations occurred in 9 to 14 percent of the babies exposed to AZT alone or a combination of AZT and lamivudine (3TC) in utero. "Both those figures are statistically significantly greater than the unexposed children," Dr. Walker said. "DNA damage accumulates through a person’s lifetime," Dr. Walker added. "These babies whose mothers received AZT and 3TC have the accumulated DNA mutations one would expect to see in teenagers." He noted that because treatment of pregnant women who are infected with human immunodeficiency virus (HIV) prevents transmission, the benefit of treatment to their infants appears to far outweigh the possibility of a risk of cancer later in life. Children who were exposed to AZT in early studies are now about six to seven years of age. "However, these studies do show that the transmission of these mutations are more than just theoretical," Walker said. Stephanie Bird, special assistant to the provost at Massachusetts Institute of Technology, Cambridge, Massachusetts, and a health ethicist, said the findings indicate that there is an ethical problem in treating mothers with the drugs. She said damage to DNA not only can result in cancer, but might also cause heart and other developmental abnormalities. Bird suggested that if the late consequences are found to be severe, parents would have to weigh the possibility of not taking drugs to prevent and then treating children who are infected. However, Dr. Walker noted that about 25 percent of children whose mothers are untreated are infected with HIV at birth. With effective treatment, that number is virtually nil.
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