"The new study, by government researchers, examined the rate of severe complications in women who delivered in U.S. hospitals in two time periods: 1998-99 vs. 2004-05.

"They found a 90% increase in blood transfusions and a 50% increase in pulmonary embolisms, or blood clots in the lungs. They also found about a 20% increase in rates of kidney failure, respiratory distress syndrome, shock and the need for a ventilator."