Maternal mortality is often associated with bygone eras and Third World countries, but some experts say more new mothers in the U.S. are dying within 42 days of childbirth. A new report says the number of women who died in California shortly after giving birth has nearly tripled in the past decade, counting 16.9 per 100,000 births in 2006. A source who worked on the study said most women died from hemorrhage, blood clots, or underlying cardiac disease. But California is not alone—the Joint Commission issued an alert in January that maternal mortality rates could be increasing nationwide. “The rate of maternal death today is not acceptable in the United States,” the president of the Joint Commission said. “We need to work much harder than we have been to reduce it.” Doctors attribute the increase to the rise of obesity, which makes mothers more likely to have other health conditions, and increasing scheduled C-sections, which show a higher rate of maternal mortality.