[Comment] Prematurity-associated lung disease: from survival to breathing well across the life course

Preterm birth is a pressing global public health challenge, with an estimated 13·4 million infants born prematurely each year and prematurity now the leading cause of death among children younger than 5 years.1 Preterm births are classified by gestational age: late preterm (34–36 weeks), moderate preterm (32–33 weeks), very preterm (28–31 weeks), and extremely preterm (<28 weeks).1 Risk of morbidity and mortality rises sharply with decreasing gestational age, and extremely preterm infants—although comprising only about 5% of all preterm births3—account for a disproportionate burden of severe health complications and death.