age of viability means
Age of viability. The age at which a premature baby can survive outside of the uterus. The age of viability occurs sometime between 22 and 26 weeks, usually when the weight is greater than 500 grams. The probability of survival is slim at 22-23 weeks, but increases to approximately 85% at 26-28 weeks. Respiratory problems are the most common complications that a preterm infant experiences.