Health claims made by private cord-blood banks to persuade parents to save their baby's umbilical cord blood can overstate the benefits, according to an investigation by CBC-TV's Marketplace.

Cord blood is the blood that remains in the umbilical cord after a baby's birth. It contains stem cells that can be used to regrow blood and bone-marrow cells and is used to treat diseases such as leukemia and some immune disorders.

In Canada, there are 12 private cord-blood banks, all offering to store frozen cord blood for years. The service is sold as a "lifesaving biological insurance" — in case the child develops a disease later in life.

But saving cord blood can be expensive, up to $3,000 over 18 years, and the chance a child will ever use the stored blood is extremely low, experts say.

Marketplace wanted to test some of the claims that private companies make to sell the service.

For instance, one ad says that the odds are good your child will need his or her stored cord blood one day, and that one child in every 50 children does.

But a B.C. transplant expert says the likelihood a child will ever need his own stem cells to treat a disease is very low.

Leukemia claim disputed

About 35 out of one million children develop leukemia each year, and leukemia is one of the more common diseases treated with cord-blood stem cells, said Dr. Kirk Schultz of B.C.’s Child and Family Research Institute.

Cord-blood banks have also claimed "a child’s own cord blood can be used to treat  leukemia."

But Schultz said this isn't true.

"If a child develops leukemia, we’re not going to use their own cord blood," he said. "That’s  because the disease is likely in the cord blood too. Almost always we want somebody else's cord blood or donor cells because they're the ones correcting that defect."

Cord blood from a brother or sister, however, could be used to treat a child with leukemia, he said. And for some parents, this is reason enough to save the blood.

Another claim is that someday, stem cells in cord blood might have the potential to treat diseases such as diabetes, Parkinson’s, stroke and spinal cord injury.

But this is still very theoretical, Schultz said.

"The theoretical application of stem cell technologies is that maybe someday we’ll be like in a science fiction movie — we can have a heart or a kidney generated from stem cells."

Finally, cord-blood banks have claimed in ads that finding a stem-cell donor is often impossible.

"How often have you not been able to find a match for umbilical cord blood?" Marketplace host Erica Johnson asked Schultz.

"Rarely," he said. "No more than five per cent of the time. So our chances of finding a donor now are excellent with the use of unrelated umbilical cord blood."

Two cord blood banks defended how they sold their services.

Bank sees breakthroughs

"Cord blood continues to save lives," Vancouver-based Lifebank said in an email: "There are scientific breakthroughs happening on a regular basis."

Mississauga-based Insception Biosciences said in an email: "We’re proud of the difference we’ve made in the lives of … our families who’ve received transplants."

The Society of Obstetricians and Gynecologists of Canada and the American Academy of Pediatrics do not routinely recommend private cord-blood banking.

Instead, the obstetricians and gynecologists recommend parents consider donating their baby's cord blood to one of three public cord-blood banks in Canada.

"By donating your child's umbilical cord blood you could save another child's life," a brochure from the society says. "The aim of a public cord-blood bank is to make umbilical cord blood stem cells a public resource and provide a supply for medical treatments."