For the first time, a large study suggests a higher rate of childhood cancer among test-tube babies, but researchers say the reason probably has nothing to do with how the infants were conceived. More likely, it's related to the genetics of the parents who turned to in vitro fertilization because of infertility, the study's Swedish authors and other experts say. Also, test-tube infants often are born prematurely and have breathing problems at birth—traits linked in other studies with increased cancer risks.
Still, cancer in these children is rare despite any elevated risks. Of the 27,000 IVF babies they tracked over 19 years, 53 developed cancer, versus 38 that would be expected in other children of the same age. "It's rather reassuring," said the study's lead author. The risk "is so small that it can't matter much for the individual parents or parents-to-be." The study exclusively examined Swedish children, and it's unclear if its results would be found in a more racially diverse population.