The limits of viability of extremely preterm infants.

Shaeffer and Avery's textbook, Diseases of the Newborn (1971), estimated the limit of viability to be around 28 weeks' gestation and/or 1000 g. Contemporarily, however, attempts are being made to resuscitate infants as early as 22 weeks' gestation. Clearly the "limit of viability" is a moving target, and the acceptable risk of intervening to attempt to "save" these small infants/fetuses is a value judgment and not one that can be answered by science. Even though the dilemma is not one that can be resolved empirically, the emphasis on resolution continues to be one of demands for "further research" by critics as well as advocates for the care of these small infants. Patrick Romanell (1912-2002) was a major philosopher in the critical naturalist movement in the United States and internationally. His observations on the tragic quality of human life and the dilemmas associated between the conflicts of good vs good rather than the epic quality of good vs evil lend themselves well to understanding the conflicts involved in determining the limits of viability of extremely preterm infants.