Most babies are born about 40 weeks after the first day of their mother's last menstrual period. But about 10 percent of babies arrive sooner. A baby born more than three weeks before his or her due date is considered premature.
Premature babies have less time to fully develop and mature in the womb. As a result, they're often at increased risk of medical and developmental problems. One of the biggest problems facing premature infants is underdeveloped lungs.
Your doctor may try to delay your baby's birth if you go into labor earlier than around 34 weeks into your pregnancy (preterm labor). Even a few extra days in the womb can give your baby's lungs a chance to become more mature. But sometimes, in spite of every effort, your baby may be born early.
Fortunately, the outlook for premature infants has improved dramatically in recent years. Great advances have been made in the care of premature infants, and even babies born as early as 23 weeks now have a good chance of survival.
