Women who use in-vitro fertilization (IVF) to become pregnant shouldn't worry that treatments place them at increased risk for cancer, suggests a study from researchers in Sweden. Published online November 18, 2010, in the journal Human Reproduction, the study compared a group of 24,000 women who had used IVF to become pregnant with 1.4 million women who had become pregnant without reporductive assistance. According to Reuters Health, researchers found that less than 2 percent of women in the IVF group developed one or more cancers within eight years of treatment compared to nearly 5 percent of women who did not undergo IVF.
Despite previous studies that had found increased cancer rates among IVF users, after accounting for the mother's age, number of previous children, smoking, and other health factors, researchers found that the overall risk of a woman developing cancer after IVF was almost 25 percent lower than among women who had not undergone the treatment.
"A couple who needs IVF does not have to be afraid that the hormone treatment used—at least those used in Sweden—will carry a risk for the woman to develop cancer," lead researcher Dr. Bengt Kallen of the University of Lund, in Sweden, told Reuters Health.
Concern over cancer risk and IVF stems from the use of hormones during IVF treatments. And when researchers looked at each cancer type separately, they did note an increased risk for ovarian cancer among IVF users. However, researchers speculate that ovarian abnormalities—the issue that might have led a woman to IVF in the first place—is the likely the cause of increased risk, and not the use of hormones.