The risk of a major complication of childbirth can be up to five times higher at one hospital versus another, a new study finds. But there's no way expectant mothers can tell the high-risk hospitals from the low — at least, not yet. A study in this month's Health Affairs is the first ever to examine hospitals' childbirth complication rates on a national basis. Authors looked at a representative sample of more than 750,000 deliveries that took place in 2010 at hospitals large and small, urban and rural, including both teaching and community institutions. Major complications include hemorrhaging, infections, vaginal lacerations and blood clots. Unlike major complications from, say, cardiac surgery, these obstetrical glitches are not generally life-threatening.