Ethical implications of the shifting borderline of viability.

Survival rates for babies born at 22 weeks of gestation are steadily improving at centers that offer active treatment to these babies. Still, many centers do not offer such treatment or, if they do, actively discourage it. Thus, parents will be given very different advice at different centers for babies born at the borderline of viability. Those doctors and centers that discourage treatment have concerns about the chances for survival, neurodevelopmental impairment among survivors, and cost. Yet there is strong evidence that many babies born at 22 weeks can survive, most survivors have good neurodevelopmental outcomes, and neonatal intensive care for tiny babies is cost-effective compared to many common and uncontroversial treatments. Given this growing body of evidence, policies discouraging or forbidding treatment of babies born at 22 weeks will require stronger ethical justification than has been given to date.