Vasectomies may not be the permanent birth control solution you thought they were

American cornerback Antonio Cromartie made headlines recently not because of any great play he made on the football field, but because he became a father – again!

What made his story stand out was not that his wife gave birth to twins but that she was pregnant at all. Already a father of 10, Cromartie had had a vasectomy in an effort to avoid expanding his family any further.

“It took me a while to process it, but Antonio stood firm and was saying, ‘It’s God’s will,’”, his wife, Terricka Cromartie, told US Weekly.

The story is enough to send shivers down the spine of any man who has “been snipped”. But, although their success rate is high, vasectomies ‑‑ just like any other medical procedure ‑‑ don’t come with a 100 per cent guarantee.

“A vasectomy is about 99.9 per cent effective in terms of preventing pregnancy,” says Dr. Ethan Grober, vasectomy reversal specialist in Toronto. “That also equates to about a one in 1,000 chance of a pregnancy after a vasectomy. That number doesn’t sound so good so most men want to go with the 99.9 per cent statistic.”

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There are two main reasons vasectomies can fail, says Vancouver’s Dr. Jack Chang, clinical instructor at the University of British Columbia and a physician at Pollock Clinics.

“One of the main circumstances where a vasectomy can fail is if the man resumes unprotected sexual intercourse right after his vasectomy,” Chang says. “This is because even after a vasectomy, there are still many live sperm in the reproductive tract that needs to be ‘flushed out’. Normally, this will take at least three months and 30 ejaculations for sperm to be eliminated from the vas deferens.” (Chang says that the failure rate at Pollock Clinics is generally one in 5,000, one of the lowest in North America.)

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Men who have undergone the procedure are routinely advised to use birth control for at least three months after their vasectomy. They’re then instructed to get their semen analyzed using a professional lab before it’s deemed safe to stop using birth control.

“That’s where things tend to break down,” Grober says. “Only about 40 per cent of men actually elect to complete the post-vasectomy testing. Moreover, men who don’t appreciate that it takes time to clear all the sperm and go out and ‘celebrate’ their reproductive freedom may be in for a surprise.”

Antonio Cromartie and wife, Terricka Cason. (Paul Zimmerman/WireImage)

Uncommonly, there is also a phenomenon called recanalization, which occurs when the two ends somehow reconnect, Chang explains.

“Early after a vasectomy, scar tissue forms between the two cut ends of the vas deferens,” he says. “Initially, this scar tissue is soft and more penetrable by motile sperm. Sometimes these motile sperm can penetrate through and cause many small holes to form through the scar causing a ‘Swiss cheese’-like appearance, allowing bypass of the obstruction.

“At the time of a vasectomy, even though the ends are typically cut, clipped and cauterized, nature somehow finds a way,” Grober says. “In very rare cases, small channels can be re-established and some sperm can sneak through. This process [recanalization] may happen very early following a vasectomy or after many years.”

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Nevertheless, vasectomies remain the safest, simplest and most cost-effective method of permanent contraception for men, Chang says. The procedure typically takes six to 10 minutes under local anesthesia.

“Most couples who have gone through the process strongly agree that a vasectomy resulted in an enhanced sex life without fear of pregnancy,” Chang says.

There’s another reason vasectomies sometimes “fail”.

“It must be at least acknowledged that infidelity with a man who hasn’t had a vasectomy accounts for some of the pregnancies in the female partner,” Grober says. “We tread very lightly on that one.”

As Chang puts it, “a vasectomy also doesn’t stop a man’s wife from having kids; it only stops her from having his kids.”

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