Nevertheless, there are also several arguments in favor of gestational age–based guidelines. Gestational age is strongly associated with the risk for death, impairment, and morbidity. There is no other time of life when the chance of survival changes so dramatically and so quickly This marks the most important difference between premature infants and the elderly. There are also particular features of decision making for extremely premature infants that support giving parents a larger role in decision making than is the norm later in life. Although neonatal intensive care is cost-effective overall for extremely premature infants,62 routine resuscitation of the smallest and most immature infants (who have a <10% chance of survival without profound impairment) would impose substantial costs on those infants and on the community for little benefit.10 Finally, the alternatives to gestational ageism also have their problems. Individualizing treatment decisions is entirely laudable, but in the absence of a framework for decisions, risks inconsistency. It is also compatible with gestational age frameworks. The most transparent and flexible approach to guidelines would be an explicit prognostic strategy for withholding or withdrawing treatment, perhaps drawing on the concept of gestational age equivalence, as just described (Table). Nevertheless, there are challenges in the development of such a framework and in its implementation.