For some men, the time of year when college basketball teams take to the court to go head-to-head in a heated tournament is the perfect moment to schedule the snip.
According to data from a large US insurance claims database, the month of March – during which the NCAA March Madness basketball tournament takes place – can see a spike in vasectomies performed.
The trend was evident in data from 2007 to 2015, and there's a plausible reason why this could be happening: men deciding to make the most of their recovery time.
"Major sporting events are a popular time for men to schedule a vasectomy because we advise them to take it easy for two to three days after the procedure," medical doctor James Dupree of Michigan Medicine explained in 2018.
"For most men, this means sitting on the couch in front of their television, and sporting events offer them something to watch while resting."
It's a narrative that makes perfect sense. If you're going to be laid up with an ice pack on your nethers, why not take full advantage and spend the time also doing something fun? But that explanation may only be a small part of the story.
The "Vas Madness" phenomenon is well known from media reports, many of which cite a since-removed 2017 blog post by healthcare IT provider Athenahealth reporting a 30 percent increase in vasectomies performed in the first week of March Madness in 2016, compared to an average week.
A vasectomy is a simple outpatient procedure used for male contraception that involves cutting or sealing the tubes that transport sperm.
In 2018, a team led by urologist Kevin Ostrowski of the University of Washington published a paper in the journal Urology, analyzing insurance claims from millions of American men to identify a rise in vasectomies performed during March, noting the increase may be related to March Madness.
March isn't the only seasonal peak, however.
The Ostrowski paper also found a spike at year's end, which the researchers attribute straightforwardly to patients having reached their annual insurance deductible, the point at which their insurer begins covering a greater share of medical costs, making elective procedures effectively cheaper.
(No one has coined a catchy name for that one yet.)
Here's where Vas Madness gets a little tangled. Once a trend becomes widely reported and promoted, it can start to reinforce itself – and the origins of Vas Madness may not be as organic as the narrative implies.
The idea appears to have entered the public conversation in 2008, when an Oregon urology clinic ran a radio ad campaign during March Madness, cheekily dubbed "Snip City".
"When March Madness approaches, you need an excuse to stay at home in front of the big screen," the ad asserted. "Get your vasectomy at Oregon Urology Institute the day before the tournament starts. It's snip city."
Within a week, the campaign was being reported on globally. Other clinics started picking up on the trend, running their own Vas Madness promotions.
By the time Ostrowski's team analyzed nearly a decade of insurance claims and confirmed that vasectomies increase in March, they may have partly been measuring the downstream effects of that original radio ad.
Further, Michigan Medicine's 2018 press release about the phenomenon centered around an announcement that the urology clinic was expanding its vasectomy services in anticipation of the rush.
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American sociologist Robert Merton called this kind of phenomenon a self-fulfilling prophecy: a prediction that – simply by being believed and acted upon – ends up coming true.
Each news article, Vas Madness promotion, and peer-reviewed paper becomes another link in the chain, making it increasingly impossible to know where organic demand ends and manufactured demand begins.
However it comes about, though, Vas Madness ultimately appears to be a net good for the patients, in more ways than one.
"Sometimes it's hard to get guys to follow post-vasectomy recovery instructions and make sure they are relaxing and not doing things they shouldn't, like strenuous exercise or activities," said urologist Alexander Rozanski of UT Health San Antonio in 2023.
"March Madness gives them a good excuse to lay low and recover."