According to a study by Dr. Meir Steiner, sleep deprivation can lead to postpartum depression. Allowing new moms to sleep in the hospital, by having their babies taken during the night (and presumably not waking them up every 4 hours to check on them) helps reduce the chances of getting it. Steiner encourages new moms to continue a restful regimen at home, telling their partners that lack of sleep may make them grumpy while it make moms depressed.