IVF and Breast Cancer
Adapted from Ovarian Stimulation for In Vitro Fertilization and Long-term Risk of Breast Cancer published in JAMA on July 19, 2016
More than five million babies have been born worldwide through In Vitro Fertilization and other assisted reproduction treatments.
Women undergoing in vitro fertilization have long worried that the procedure could raise their risk for breast cancer. The IVF treatment requires temporarily increasing levels of estrogen five to 10 times compared with the normal, unstimulated levels. Estrogen and the related hormone progesterone can affect the course of some of the breast cancers.
The largest, most comprehensive study to date from researchers in the Netherlands provides reassurance: It found no increased risk of breast cancer among women who have undergone the IVF treatment.
Among women undergoing fertility treatment in the Netherlands between 1980 and 1995, the use of in vitro fertilization compared with non-IVF treatment was not associated with an increased risk of breast cancer after a median follow-up of 21 years, according to the study.
Researchers followed over 19,000 Dutch women who had IVF treatment in one of the Netherlands' fertility clinics. The non-IVF group consisted of 6,000 Dutch women who underwent other forms of fertility treatments at Dutch fertility clinics at the same time.
At the end of the follow up period, 839 cases of invasive breast cancer and 109 cases of in situ breast cancer were documented.
The risk for breast cancer among the women who had IVF was similar to the risk of women who didn't have IVF, the researchers found. The cumulative rate of breast cancer was 3.0 percent for the IVF group, compared to 2.9 percent for the non-IVF group.
The study's authors also found that the type of fertility drugs the women received had no effect on their risk for breast cancer.
Based on their exhaustive study, the authors conclude that they failed to find an association between IVF treatment and the long-term risk of developing breast cancer.