The price of preventing preterm labor is about to go through the roof. A drug for high-risk pregnant women has cost about $10 to $20 per injection. Next week, the price shoots up to $1,500 a dose, meaning the total cost during a pregnancy could be as much as $30,000. 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 government approval to exclusively sell the drug, known as Makena. The March of Dimes and many obstetricians supported that because it means quality will be more consistent and it will be easier to get. None of them anticipated the dramatic price hike, though -- especially since most of the cost for development and research was shouldered by others in the past.