How is the premature infant diagnosed?

Usually a woman knows how many weeks she has been pregnant. The healthcare provider measures the size of pregnant woman's womb to help confirm the dates, but if there is any doubt, the best information is obtained from a pregnancy ultrasound . This test uses high frequency sound waves - much safer than X-ray for the unborn infant - to measure the size of the baby's head and look for other indicators of development. After the baby is born, the healthcare provider can estimate the baby's age by doing a physical exam.