Infant born before 37 weeks of gestation regardless of birth weight. A premature infant is usually of low birth weight; has incompletely developed organ systems; appears thin, with little subcutaneous fat; has a large head; and pinkish, translucent skin. The cause of prematurity is unknown in many cases, but in some is associated with toxemia, multiple pregnancy, chronic disease, trauma, or poor nutrition. The prognosis depends on the maturity of the various organ systems of the infant’s body and on the postnatal care given, the best care being provided in neonatal intensive care units. Treatment involves maintenance of stable body temperature and respiration, provision for adequate fluid and nutrient intake, and prevention of infection. Also called preterm infant.