Previous studies have shown that both exogenous and endogenous estrogens and progestogens increase the risk of breast cancer. it has been suggested that in vitro fertilization (IVF) procedures may increase breast cancer risk. This risk could be could be due to a temporary decrease in estradiol and progesterone levels (during down-regulation of the natural cycle), as well as strongly elevated levels (during stimulation phase). Results of previous studies investigating breast cancer risk after IVF treatment were inconclusive because of limited follow-up. Recent studies have reported no increased risk of this cancer after IVT at a mean follow-up of 8 and 16 years.
展开▼
