All About Baby
By week 16, your baby-to-be's body is doing more to support itself. Her kidneys function and produce urine that then passes through the umbilical cord. Within her stomach, bile is secreted, although she relies on you for all of her nutrients. Her appearance changes as her scalp hair grows and may even have color. Her developing facial muscles make it possible for her to open and close her mouth, maybe even give you a smile or two.
This week, your little one is around 4.5 inches long (crown to rump) and weighs in around 3 ounces. Baby is about the size of an avocado.