The body of evidence suggests that breast cancer risk is not increased after in vitro fertilisation (IVF), but is limited by lack of long-term follow-up data. In a recent Dutch cohort study of over 19,000 women treated with IVF between 1983 and 1995 and followed for a median of 21 years, the risk of breast cancer was similar to that in subfertile women not treated with IVF and in the general population, adjusted for parity and age at first birth. Among 25,108 women (mean age at baseline, 32.8 years; mean number of IVF cycles, 3.6), 839 cases of invasive breast cancer and 109 cases of in situ breast cancer occurred after a median follow-up of 21.1 years.
Breast cancer risk in IVF-treated women was not significantly different from that in the general population (SIR, 1.01 [95% CI, 0.93-1.09]) and from the risk in the non-IVF group (HR, 1.01 [95% CI, 0.86-1.19]). The cumulative incidences…
