A preterm newborn is a baby delivered before 37 weeks of gestation. Depending on when they are born, preterm newborns may have underdeveloped organs that are not be ready to function outside of the uterus.
A previous preterm birth, multiple gestation (such as twins), poor nutrition during pregnancy, lack of regular prenatal care, infections, use of assisted reproductive technologies (such as in vitro fertilization), and high blood pressure can increase the risk of a preterm birth.
If organs are underdeveloped, preterm newborns may have difficulty breathing and feeding and are prone to bleeding in the brain, infections, and other problems.
Preterm birth can sometimes be delayed for a brief period by giving the mother medications to slow or stop contractions.
When an infant is expected to be delivered significantly early, doctors can give the mother injections of a corticosteroid to speed the development of the fetus’s lungs and help prevent bleeding in the brain (intraventricular hemorrhage).
The earliest and smallest preterm newborns are at far greater risk of having problems, including developmental problems.
Although some preterm newborns grow up with permanent problems, the majority have mild or no long-term problems.
Gestational age refers the number of weeks of pregnancy. The gestational age is determined by counting the number of weeks between the first day of the mother''s last menstrual period and the day of delivery. This time frame is often adjusted according to other information doctors receive, including the results of early ultrasound scans, which give additional information regarding the gestational age. The baby is estimated to be due (the due date) at 40 weeks of gestation.
Newborns are classified by gestational age as preterm if they are delivered before 37 weeks of gestation. Preterm infants are further categorized as
Extremely preterm: Delivered before 28 weeks of gestation
Very preterm: Delivered at 28 to before 32 weeks of gestation
Moderate preterm: Delivered at 32 to before 34 weeks of gestation
Late preterm: Delivered at 34 to before 37 weeks of gestation
In 2023, about 1 of every 10 infants born in the United States was born before they were full term. Greater degrees of prematurity are associated with greater risks of serious and even life-threatening complications.
Extreme prematurity is the single most common cause of death in newborns. Also, newborns born very prematurely are at increased risk of long-term problems, especially delayed development, cerebral palsy, and learning disorders. Nonetheless, most infants who are born prematurely grow up with no long-term difficulties.
