Dr. Peter Boylan:

Viability refers to the ability of some babies to survive outside of the womb. The committee heard evidence last week from the masters of the Rotunda and National Maternity Hospital about how we define viability as 24-weeks' gestation. Some babies can survive if they are born at 23 weeks while some babies born at 25, 26 or 27 weeks will not survive because they are not developed enough to survive. Among the survivors, there is a high rate of disability. That is why viability is important. For example, if a mother develops severe high blood pressure at 24 weeks, we will intervene. As the baby is viable, we will make every effort to save the baby. If a woman develops the same degree of hypertension at 20 weeks, there is no point in trying to save the baby because it has zero chance of survival at 20 weeks. That is the difference between pre-viable and viable.