The price of preventing preterm labour is about to go through the roof in the U.S.

A drug for high-risk pregnant women has cost about $10 to $20 per injection. Next week, the price shoots up to about $1,450 a dose, meaning the total cost during a pregnancy could be as much as $29,000.

That's because the drug, a form of progesterone given as a weekly shot, has been made cheaply for years, mixed in special pharmacies that custom-compound treatments that are not federally approved.

But recently, KV Pharmaceutical of suburban St. Louis won U.S. government approval to exclusively sell the drug, known as Makena or hydroxyprogesterone caproate. The March of Dimes and many obstetricians supported that because it means quality will be more consistent and it will be easier to get. It is not listed in Health Canada's online database of approved drugs.

None of the groups anticipated the dramatic price hike, though — especially since most of the cost for development and research was shouldered by others in the past.

"That's a huge increase for something that can't be costing them that much to make. For crying out loud, this is about making money," said Dr. Roger Snow, deputy medical director for Massachusetts' Medicaid program.

"I've never seen anything as outrageous as this," said Dr. Arnold Cohen, an obstetrician at Albert Einstein Medical Center in Philadelphia.

Doctors say the price hike may deter low-income women from getting the drug, leading to more premature births. And it will certainly be a huge financial burden for health insurance companies and government programs that have been paying for it.

The cost is justified to avoid the mental and physical disabilities that can come with very premature births, said KV Pharmaceutical chief executive Gregory J. Divis Jr. The cost of care for a preemie is estimated at $51,000 in the first year alone.

Affordability questions

"Makena can help offset some of those costs," Divis told The Associated Press. "These moms deserve the opportunity to have the benefits of an FDA-approved Makena."

The U.S. Food and Drug Administration is not involved in setting the price for the drugs it approves.

A KV subsidiary, Ther-Rx Corp., will market the drug. It has announced a patient assistance program designed to help uninsured and low-income women get the drug at little or no cost.

But Snow and others said someone is going to have to pay the higher price. Some of the burden will fall on health insurance companies, which will have to raise premiums or other costs to their other customers. And some will fall on cash-strapped state Medicaid programs, which may be forced to stop paying for the drug or enroll fewer people.

"There's no question they can't afford this," said Matt Salo, executive director of the National Association of Medicaid Directors.

Salo and Snow said they do not know how many state Medicaid programs currently pay for Makena, which as a generic, hydroxyprogesterone caproate,  was recommended by the American College of Obstetricians and Gynecologists.

Makena is a synthetic form of the hormone progesterone that first came on the market more than 50 years ago to treat other problems. Hormone drugs came under fire in the 1970s, following reports they might damage fetuses in early pregnancy. In the 1990s, the early incarnation of Makena was withdrawn from the market.

But the drug got a new life in 2003, with publication of a study that reported it helped prevent early births to women who had a history of spontaneous preterm deliveries.

These very early births produce children who — if they survive — need months of intensive care and often suffer disabilities. The cause of sudden preterm delivery is not understood, but it occurs in black mothers at much higher rates than whites or Hispanics.

The study of women at risk for this condition found that only about 36 per cent of those given the progesterone drug had preterm births, compared with 55 per cent among those not on the drug.

It's believed the treatment calms the muscles of the uterus, experts said.

Common side-effects included pain, swelling or itching at the injection site; hives, nausea and diarrhea, according to the FDA. Serious adverse reactions are rare, although there was a report of a blood clot in the lungs and another of infection at the injection site, the agency noted.