For most of us, our connection to an umbilical cord lasts only during our first few seconds of life.
However, for a growing number of people, umbilical cords represent a crucial lifeline even in adulthood.
Take Rhonda Kottke, for instance. On Dec. 28, 2001, at the age of 29, her doctor diagnosed the Chicago woman with leukemia.
Her treatments ravaged her immune system to the extent that if it were not replaced, she would die.
Kottke's siblings were tested, but their bone marrow was not a close enough match to hers. It was then that her doctors suggested a different course of treatment altogether -- an infusion of stem cells obtained from an umbilical cord.
The transplant came six months after her diagnosis. Today, doctors say the graft likely saved Kottke's life.
"I'm doing great, knock on wood," she told ABC's "Good Morning America." "I have no signs of leukemia in my blood. I have no sign of cancer at all. I'm as healthy as anyone else."
Kottke received her transplant from a public cord cell bank. However, many private companies offer new parents the chance to freeze their child's cord cells for personal use -- that is, if the child or a family member needs them.
But as the trend of banking cord blood continues to grow, critics say those who bank umbilical cord cells at private banks will most likely never use it.
And with an initial price tag of more than $1,000 to store the cord blood -- and yearly storage fees in the hundreds of dollars -- the cost of this biological insurance policy may outweigh the actual benefits for most.
At birth, the umbilical cord is normally thrown away. But in the past few years, doctors have discovered that it is chock full of stem cells, which can be used to treat as many as 70 different diseases.
Treatments using cord blood cells are still relatively new; so far, only about 6,000 Americans have received cord blood transplants. Most commonly, the cells are used to regenerate the immune systems of patients who have received treatment for leukemia.
"Cord blood is an increasingly valuable alternative to bone marrow transplant," says Dr. Curt Freed, head of clinical pharmacology and toxicology at the University of Colorado School of Medicine.
However, researchers say that future applications could be far broader. But, though cord blood treatments appear promising, much of the science surrounding these treatments is still speculative.
"There may be technology developed in the future that allow patients and parents to find it useful in a clinical setting, but there is a lot of science needing to be performed before any of this stem cell hype becomes reality," says Bryon Petersen, associate professor of pathology at the University of Florida.
Joshua D'Eramo's parents privately stored his umbilical cord blood when he was born. It was an expensive decision -- they paid their company $1,200 up front and $100 each year to store it.
"It's like an insurance policy," says his mother, Rena. "We get insurance for our cars, for a car accident and we may never need it, but it is comforting to know it is there if you do need it."
Today there are 25 private companies that will store a baby's cord blood for a fee. Like a bank account, it will be available exclusively to the family of the donor.
But the chances that anyone will ever need to make a withdrawal from such an "account" may be slim.