A mother's age, weight, smoking status and the number of miscarriages she'd already had didn't appear to affect a child's cancer risk. A multiple birth pregnancy also didn't appear to affect the risk of cancer.
Cancers of the blood, such as acute lymphoblastic leukemia, were the most common, affecting 18 children. The next most common were cancers of the eye or central nervous system, affecting 17 children.
Although it's not clear what's to blame for the increase, the study authors think it's unlikely that IVF is at the root of the increased risk of cancer.
"This study is interesting and thought-provoking, and it adds to our growing knowledge of potential IVF consequences," said Dr. David Cohen, chief of reproductive medicine at the University of Chicago.
"But, it's difficult to think what the biological plausibility would be. If it were something that occurs during the in vitro process or some substance in the media used, I would think that it would cause a much higher number of cancers. This may just be a statistical oddity," he added.
"This is the largest study that I'm aware of, and it does suggest an increased risk of childhood cancers ... but it doesn't really delineate whether it's the IVF process or the patient selection. Is this increase due to the procedure, or is it secondary due to a difference in the patient population?" said Dr. Edward Illions, a reproductive endocrinology specialist at the Montefiore Medical Center in New York City and the Montefiore Institute for Reproductive Medicine in Hartsdale, N.Y.
The three experts do not believe these findings will have a significant influence on a couple's decision to have the IVF procedure.
"The absolute risk is so small that it will hardly influence the decision to get an IVF," Kallen said.
"This adds more information to the [pre-IVF] counseling session, but I don't think it will change the decision. The absol
All rights reserved