A troubling report that actor Dennis Quaid’s newborn twins received a dangerous overdose of the blood-thinning drug Heparin highlights the many medical mistakes made in U.S. hospitals each year.

Last year, six newborns at Methodist Hospital in Indianapolis were given an overdose of the same blood-thinning drug and three died.

The twins, born to Quaid and his wife, Kimberly Buffington, are expected to recover from the overdose, according to media reports.

Zoe Grace and Thomas Boone were born Nov. 12 at Cedars-Sinai Medical Center in Los Angeles. Celebrity Web site TMZ reported Tuesday that the twins were given 10,000 units of Heparin, rather than the 10-unit dosage they should have received.

Alice Garner, associate neonatologist at Long Island College Hospital in Brooklyn Heights, N.Y., told FOXNews.com Wednesday that all premature babies get Heparin in their IV catheters to prevent clotting.

"Heparin is used because the IV lines are so tiny," she said. "It’s necessary for the babies to survive."

Cedars-Sinai has taken full responsibility for the overdose that nearly killed the twins.

"This was a preventable error, involving a failure to follow our standard policies and procedures, and there is no excuse for that to occur at Cedars-Sinai," hospital Chief Medical Officer Michael Langberg said.

Garner said an overdose of drug can be devastating causing babies to bleed out from multiple areas in the body.

“If they get a large dose, they may bleed because their body is not going to be able to clot and this can cause all kinds of problems,” she said. “It's really devastating if you bleed in your brain. You can also bleed in your lungs, in your GI tract, you can bleed anywhere."

Garner said the mistake may have occurred because hospital pharmacies often stock adult and infant doses of medications, including Heparin.

"The error could occur at any stage," she said. "Some places have a pharmacy that prepares the IV fluids. Other places, the nurses do it. So it just depends on who prepares the IV fluids."

Hospital errors do not just affect infants. The Institute of Medicine of the National Academies estimates that about 1.5 million patients are victims of hospital errors each year.

A study from health care ratings company HealthGrades found there were more than 1.16 million safety incidents involving Medicare patients between 2003 and 2005. During that three-year period, there also were 247,662 potentially preventable deaths involving Medicare patients, the study found.

The Bush administration in August announced that Medicare no longer would pay for preventable hospital errors including injuries and infections.

Patients develop 1.7 million infections in hospitals each year and infections kill about 99,000 people a year, according to the Centers for Disease Control and Prevention.

Garner said hospitals must work to eliminate mistakes, especially those involving the tiniest of patients.

In the case of Quaid’s twins, she said, "You have to try to have the right vials in the right areas so that mistake doesn't happen. Especially with newborns, it's extremely important because adult doses are so much higher."

Quaid also has a son with his former wife, actress Meg Ryan. He starred in "Great Balls of Fire!," "Any Given Sunday," and other films.

The Associated Press contributed to this story