Frozen Sperm May Last for Generations

Potential contamination, though, may limit future use

It gives new meaning to the word "absentee father."

While many people may not know it, frozen sperm appears to last for a very long time, perhaps even for generations. And the idea of keeping sperm frozen indefinitely has some people wondering if children could be conceived by the sperm of men who are long dead.

"It's an odd concept, [but] I think it will happen," Alan Thornhill, director of the Mayo Clinic's In Vitro Fertilization Clinic in Rochester , Minn. , told HealthDay .

"I find it amazing that most people think when something is in the freezer, so to speak, it must deteriorate the same way your chicken deteriorates in the freezer," Dr. Richard Paulson, director of the University of Southern California's Fertility Program, told HealthDay . "And, of course, it doesn't."

Once sperm is frozen in liquid nitrogen, its biological activity ceases, which means it does not deteriorate. The biggest risk to sperm comes when it's thawed. Up to 70 percent of sperm dies during thawing, but usually enough survives to allow fertilization, Thornhill said.

No one knows how long sperm can be frozen, but experts say it could last hundreds of years.

But there is a catch.

When sperm is brought out of suspended animation, the germs inside it come back to life, too.

That's why U.S. fertility doctors cannot fertilize women with stored sperm until they wait six months to see if the donor has developed a disease, such as HIV or hepatitis.

The six-month quarantine has not stopped members of the American military from donating sperm before heading off to duty in Iraq . Other men store their sperm when they're worried they won't be fertile in the future, perhaps because of medical treatments such as radiation and chemotherapy.

The Mayo Clinic hopes to encourage more men to store their sperm as they face such treatments, Thornhill said.

Some men even provide sperm for freezing before they have vasectomies, in case they change their minds.

Private laboratories, hospitals and university medical centers provide sperm banking services -- and prices for services differ. Sperm banks usually charge several hundred dollars to process a specimen for freezing, and then a few hundred dollars a year for sperm storage. These costs usually are not covered by insurance.

But what if a man wants to do some really long-term planning and pass on his genes to children in 50 or even 100 years? They can try, but as doctors cure more diseases in the future, they may be unlikely to want to risk fertilizing women with old, potentially contaminated sperm, experts say.

For now, however, the focus seems likely to remain on men who are looking at the short term because of potential problems, such as illness.

"I would imagine that with increased public awareness there will be more and more utilization of this," said Dr. Benito Villanueva, a gynecologist and reproductive endocrinologist in San Diego . "The techniques and the technology are absolutely there."