1. Why did my baby lose almost a pound between his birth and when we took him home from the hospital?

It's common for a newborn to lose about 10 percent of his birth weight within his first two days, says Judith Groner, M.D., clinical associate professor of pediatrics at Ohio State University School of Medicine, in Columbus. It's simply fluid that he no longer needs once he's born. The amount of extra fluid varies by baby, so that some infants lose slightly more than 10 percent of their birth weight and others don't lose any weight at all. Most regain what they shed within a week or two.

Babies who are breastfed may take a few days longer to return to their original weight. That's because it can be three or four days before a mother's milk comes in, and several days after that for the baby to establish a regular eating pattern.