Intrauterine hormonal contraception devices are widely used among Danish women. Cases of breast cancer have been reported in women using the devices and studies have found evidence of an increased risk, but a new meta-analysis did not find an increased risk. The reported relative risks in some of the studies are numerically substantial as quoted in this review, but it is very important that physicians take absolute numbers into account when interpreting risk in order to provide the best guidance of patients with regard to contraception and associated risks.