The time period at which a foetus can survive and live a life independent of the mother’s body is now with medical techniques around six months of pregnancy; theoretically, up to that time the foetus should be considered part of the woman’s body and an abortion allowed up to then. In practice, it seems advisable that a cut- off date for legal abortion should be established, after which a viable foetus could be considered as a person having a legal personality and protected by the law; it would seem reasonable that such cut-off date could be established at five months of pregnancy since this would come close to the period of extra-uterine viability. After that period no abortions should be authorized.
UPDATE: From Campaign Life Coalition:
Morgentaler showed signs of moving away from his earlier strident position in this issue when in 2004 he decried late-term abortions saying, "We don't abort babies, we want to abort fetuses before they become babies. Around 24 weeks I have ethical problems doing that.” Even in the case of severe fetal defects or teenage pregnancies, Morgentaler said that his clinics "usually counsel the woman to continue the pregnancy and put it up for adoption if she is unable to care for it."