Breast cancer risk does have a link to taking fertility treatments, but researchers believe the relationship differs depending on if the woman gets pregnant or not after treatment.
ABC News reports that researchers with the National Institutes of Health have found that, while fertility drugs seem to reduce breast cancer risk in younger women, that risk actually increases when they become pregnant.
Many studies have attempted to pinpoint what the actual risk is, with some showing a reduction in risk, others showing increased risk, and others even showing no change at all.
Med Page Today reports that Clarice Weinberg, PhD, with the National Institute of Environmental Health Sciences in Research Park Triangle, N.C., along with her colleagues, have completed a retrospective, sister-matched case-control study with women who have used fertility drugs.
They found that women who had used the drugs but had not conceived a 10-plus-week pregnancy under treatment, there was a significant decrease in risk of breast cancer when compared with non users.
However, women who used fertility drugs and conceived a 10-plus-week pregnancy showed a statistically significant increase in breast cancer risk when compared to women who were treated, but did not become pregnant. The group noted that:
“Our data suggest that exposure to a stimulated pregnancy is enough to undo the reduction in risk associated with a history of exposure to ovulation-stimulating drugs.”
ABC News reports that Dr. Marcelle Cedars, a professor of reproductive endocrinology at the University of California, San Francisco, who was not involved in the study, states that the findings are actually a reason that more women want to take fertility drugs. She explained:
“Even in the group at an increased risk after their pregnancy, their risk was not higher than the general public. If you use fertility drugs, you’re not increasing your risk [of breast cancer].”