Narrator: This is Science Today. Expectant moms have long been told to 'eat for two', but Kathryn Lee, a professor of nursing at the University of California, San Francisco says a mom-to-be also needs to sleep for two. In fact, Lee has conducted studies looking into the sleeping patterns of expectant mothers and concluded that postpartum depression is really the result of sleep deprivation.
Lee: The symptoms are very similar. If someone's deprived of sleep on a chronic basis without a chance to make it up on the weekends or after a few days, they start to feel irritable, confused, disoriented. You are not really able to concentrate or think really clearly and you have cognitive problems processing information.
Narrator: Lee says probably because of hormonal changes and stress, expectant mothers in her study had less of restorative deep sleep.
Lee: They have to adjust to that and get more sleep at night - half an hour more sleep, which can make a big difference.
Science Today, I'm Larissa Branin.