Delivery before the 37th week is called a premature, or preterm, delivery. A premature delivery can cause problems for the infants if their organs are not fully developed. Infants delivered before 32 weeks have greater health risks than those who are delivered at 32 weeks of gestation or later.
Multiple pregnancies seldom reach the usual 40-week due date:1
After delivery, most premature babies need care in a hospital unit called the neonatal intensive care unit (NICU). Care in the NICU can last days or weeks, depending on a baby's condition and the amount of specialized care the baby needs.
For more information, see the topics Preterm Labor and Premature Infant.
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WebMD Medical Reference from Healthwise