April 22, 2026
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Male infertility may serve as an early-warning sign for certain diseases, including colorectal and thyroid cancer, a new study says.
After a couple goes through infertility treatment, men with a low sperm count or a lack of sperm may not get any follow-up medical care.
But research over the past decade has found that male infertility is linked to an increased incidence of health issues, including diabetes, cardiovascular disease, metabolic disease and testicular cancer.
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A new study, published Tuesday, shows that men with infertility also are at a higher risk for colon and thyroid cancer, giving further evidence that male reproductive health may be an indicator of overall health and an early-warning sign of problems.
"Most men who undergo fertility testing are between 30 and 35 years old," one of the study's authors, Angel Elenkov, of Lund University in Sweden, said in a news release. "The aim is to help them become fathers, and there is no subsequent follow-up on their health. These findings are important from a public health perspective given that cancers of the colon and rectum, as well as thyroid cancer, are on the rise among younger people. These cancers could be prevented through early screening."
Infertility affects nearly 190 million people around the world. Among couples, men are the cause of infertility about 50% of the time.
There are a variety of types of male infertility, including low sperm count, or oligospermia, and lack of sperm in semen, or azoospermia.
Some cancer treatments, injuries to the testicles, hormonal issues, some autoimmune diseases and other issues also can affect male fertility, according to the Cleveland Clinic.
Genetic disorders may cause infertility, which may partially explain the higher incidence of disease, according to the researchers.
"One theory is that if something goes wrong at the genetic level – which can manifest as reduced sperm quality – other systems in the body may also be affected, increasing the risk of disease," Elenkov said.
"It has previously been found that men with severely reduced fertility are at increased risk of developing testicular and prostate cancer," Michael Kitlinski, one of the researchers, said in the news release. "That is why we wanted to investigate whether there is also a link to other forms of cancer."
For the study, the researchers used registry data from more than 1 million Swedish men who had had their first child between 1994 and 2014. More than 14,500 of those men underwent intracytoplasmic sperm injection, or ICSI, a form of in vitro fertilization in which a single sperm is injected into an egg. The embryo is then transferred into a woman's womb, which may result in a viable pregnancy.
Comparing those results to the national cancer registry, the researchers found that men who became fathers with the help of ICSI were two times more likely to develop colorectal cancer and three times more likely to develop thyroid cancer than men who became fathers without ICSI.
The researchers noted the infertility treatment was not the cause of the cancers and that the overall rate of cancer in men who underwent ICSI was low among men ages 30 to 35.
