The biggest fear of women who undergo assisted reproduction is the possibility of IVF drugs to cause ovarian cancer, either due to repeated use of stimulation drugs, either due to permanent ovarian aspirations. In a large study published in Human Reproduction in 2010. this proved to be incorrect.

The records of over 24,000 women who have given birth to a child from assisted fertilization in Sweden, from 1982 to 2006, were included in the analysis. A total of about 1.4 million data were analyzed. 1279 women who underwent the IVF procedure were found in the cancer register and their data were compared to infertile women who were not in the IVF procedure, and with data of other women enrolled in the cancer register.

The results are somewhat surprising. Women who are infertile but have never been treated with IVF have a higher risk for cancer, especially ovarian (OR 1.37), while women in IVF have this risk reduced (OR 0.74) compared to the first group.
The results show that although infertile women seem to have an increased risk for ovarian cancer, it is unclear whether the same mechanism leads to infertility and elevated risk for cancer. Also, it seems that the infertility treated by IVF reduces this risk.