📖 Definition
Any birth occurring before 37 completed weeks of gestation. Premature infants (preemies) are at risk for respiratory distress syndrome, brain bleeds, infection, feeding difficulties, and developmental delays — with risk increasing the earlier the birth. Extremely preterm (under 28 weeks), very preterm (28–32 weeks), and moderate-to-late preterm (32–37 weeks) are recognized sub-categories.