Infertile men are more likely to develop aggressive early-onset prostate cancer, new research suggests.
Those who are unable to have children naturally or via IVF are overall 47 per cent more likely to develop the life-threatening condition, while men under 50 have three times the risk, a Swedish study found today.
Undiagnosed prostate tumours may drive infertility, while low testosterone levels could lead to the development of both conditions, according to the researchers.
Early-onset prostate cancer affects around one in every 1,000 fathers under 50.
Around 35 per cent of men have poor fertility while two per cent are unable to father children.
How the research was carried out
The researchers, from Lund University, analysed all fathers and their first born children in Sweden between 1994 and 2014.
Information was taken from birth, cancer and assisted reproduction registers.
Fathers who underwent intracytoplasmic sperm injections (ICSI) were compared against those who became parents naturally or via IVF.
ICSI involves doctors injecting a single sperm into an egg. This is different to IVF, which mixes sperm with eggs and allows them to fertilise.
It generally costs up to £1,000, on top of IVF fees, and is recommended for men with very low sperm counts or who have previously struggled to have children.
Men seeking fertility treatment should be screened for cancer
Results suggest men who have ICSI are at a significantly higher risk of early-onset prostate cancer but not late.
IVF does not influence men's risk of any type of the disease.
ICSI itself does not raise men's likelihood of developing prostate cancer, however, infertile men may opt for the treatment in a last ditch attempt to become fathers.
Study author Yahia Al-Jebari said: 'The increased risk of prostate cancer is definitely not because of the ICSI treatment per se, which we know has no biological impact on the male.
'In Sweden, ICSI is reserved for those men who cannot conceive through IVF and generally have very poor semen quality'.
The fertility treatment could therefore be used as a screening tool for prostate cancer diagnoses, according to the researchers.
Infertile women are over 50% more likely to become pregnant if they are treated with two hormones
This comes after research released last March suggested infertile women are more than 50 per cent more likely to become pregnant if they are treated with two key hormones.
Among infertile women undergoing IVF after two unsuccessful attempts, 54.3 per cent become pregnant and 51.4 per cent go on to have a live birth after receiving the growth hormones estradiol and progesterone, a study found.
This is compared to just 17.1 per cent of women who try IVF for a third time without these hormones, the research adds.
Estradiol and progesterone are thought to improve blood flow to the lining of the uterus, preparing it for egg implantation.
Researchers plan to investigate whether women suitable for such treatment can be identified before having to endure repeated IVF failures.