ABC of preterm birth: Epidemiology of preterm birth
Preterm birth is a major challenge in perinatal health care. Most perinatal deaths occur in preterm infants, and preterm birth is an important risk factor for neurological impairment, including cerebral palsy. Preterm birth not only affects infants and their families—providing care for preterm infants, who may spend several months in hospital, has increasing cost implications for health services.
Preterm birth is the delivery of a baby before 37 completed weeks' gestation. Most mortality and morbidity affects “very preterm” infants (those born before 32 weeks' gestation), and especially “extremely preterm” infants (those born before 28 weeks of gestation). In the past 20-30 years advances in perinatal care have improved outcomes for infants born after short gestations. The number of weeks of completed gestation that defines whether a birth is preterm rather than a fetal loss has become smaller. In 1992 the boundary that required registration as a preterm live birth in