#asktheexperts 2-month-old baby didn't urinate the whole night. her diaper was dry when i checked in the morning. should I worry about it.

A. Your newborn pees all day and night because his bladder is very small, even a small accumulation of pee can cause his body to expel it as a reflex action. However, as your baby grows, his bladder capacity will increase, and his body will start to produce a hormone that prevents him from peeing at night.