Deliveries before 37 weeks of pregnancy are considered “preterm” or premature:
- Labor that begins before 37 weeks of pregnancy is preterm or premature labor.
- Birth that occurs before 37 weeks of pregnancy is a preterm or premature birth.
- Infant born before 37 weeks in the womb is a preterm or premature infant.
- “Late preterm” refers to 34 weeks through 36 weeks of pregnancy. More than 70% of preterm infants are born during the late-preterm time frame. Late-preterm infants typically have better health outcomes than those born earlier, but they are still three times more likely to die in the first year of life than are full-term infants.
Preterm labor occurs between 20 and 36 6/7 weeks of pregnancy. Preterm birth is the most common cause of infant death. It is the leading cause of long-term disability in children. Many organs, including the brain, lungs, and liver, are still developing in the final weeks of pregnancy. The earlier the delivery, the higher the risk of serious disabilities such as cerebral palsy, developmental delays, and vision and hearing problems.
Preterm births can also take a heavy emotional and economic toll on families.