premature babies who survive are typically born during the
A premature birth is a birth that takes place more than three weeks before the baby is due. In other words, a premature birth is one that occurs before the start of the 37th week of pregnancy. Normally, a pregnancy usually lasts about 40 weeks. Premature birth gives the baby less time to develop in the womb. Premature babies, especially those born earliest, often have complicated medical problems.