"new research shows that those last weeks of pregnancy are more important than once thought for brain, lung and liver development. And there may be lasting consequences for babies born at 34 to 36 weeks, now called "late preterm."
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"The American College of Obstetricians and Gynecologists, the American Academy of Pediatrics and the March of Dimes are now urging obstetricians not to deliver babies before 39 weeks unless there is a medical reason to do so."