Male infertility linked to risk of prostate cancer

Poor sperm function (male infertility) causes nearly half of all infertility. The observation that poor sperm function is commonly associated with developmental genitourinary defects such as cryptorchidism suggests that male infertility could be a risk marker for later disease. Unfortunately, we know little about the natural history of male infertility beyond reproductive life, owing to historical social stigma experienced by affected men. Studies shedding light on the future health of infertile men should be welcomed, and in the linked paper (doi:10.1136/bmj.l5214) Al-Jebari and colleagues report analyses of registry data from the whole population of Sweden over 20 years. Their results provide the strongest evidence to date that risk of prostate cancer may be increased in infertile men. Importantly though, a causal relation cannot be assumed.1

Al-Jebari and colleagues included 1.2 million men in Sweden who fathered a first born child during the …