A broad consensus among scientists and clinicians holds that male fertility has declined in recent decades, even as the reasons remain elusive.

The trend is supported by population data, yet experts do not agree on whether this marks a crisis or a natural shift in reproductive timing.

Social media chatter has pointed to environmental exposures as potential factors, including devices and electric vehicles.

“This is the canary in the coal mine,” Levine, public health physician at the Hebrew University-Hadassah Braun School of Public Health, told National Geographic.

“It signifies that something is very wrong with our current environment, as lower sperm counts predict morbidity and mortality.”

“At least one-third of couples we evaluate have some male component,” he noted.

“There is no evidence to suggest that this decline is the cause of a precipitous decline in the ability to cause pregnancies,” primary study author Scott Lundy, a reproductive urologist at Cleveland Clinic, told NatGeo.

“Most men, even with a modest decline in sperm counts, will still have no issues conceiving.”

A Cleveland Clinic analysis of studies from the last 53 years found sperm counts to be steady. That finding challenges narratives of a rapid collapse in male fertility.

Multiple lifestyle factors can lead to a decline in male fertility, including obesity, smoking and diet, as well as environmental exposures and delayed parenthood.

National Geographic also reported that heavy drinking and marijuana use directly contribute to declining fertility, and that quitting these habits, while also exercising and losing weight, can help.

Systemic inflammation, infection and disease can also have a big, profound effect on the current status of fertility.

Those who are getting over a fever from an infection, like the flu or COVID, will have a drastically lower sperm count for three months.

“Poor semen parameters are associated with other medical conditions and may signal underlying metabolic, hormonal or environmental issues,” he said.

“The decline could be caused by increased use of contraception, as well as men waiting longer to have children or choosing not to have them at all.” Experts note that men seeking fertility help should consult a urologist to evaluate the issue.