[OnyxCougar]

No consensus and no compromise appears possible:

To a person who believes that a human person is created at conception, abortion is a form of murder. Some pro-life individuals and organizations have suggested that an abortion clinic is the ethical equivalent to a Nazi death camp. They have suggested that embryo research is the equivalent of the fabrication of lampshades made from human skin in those same death camps. Some pro-lifers suggest that delaying the start of personhood beyond conception is analogous to the thought processes of slave owners. Afro-American slaves were once recognized as forms of human life, but not regarded as full persons. Similarly, during the Shoah -- the Nazi Holocaust -- Jews were considered as sub-human.
To a person who believes that human personhood begins at the start of the second trimester or later, a first trimester abortion (i.e. during the three months following conception) is a regrettable option, but often the most ethical choice for a pregnant woman who does not wish to continue pregnancy for emotional, mental, physical, or economic reasons.

The medical profession appears to follow the viability criteria. Medical societies enforce regulations prohibiting essentially all abortions after (typically) 20 or 21 weeks of pregnancy. The US Supreme Court also seems to have used fetal viability as a significant event; it allows states relative freedom to prohibit abortions after viability for a wide range of reasons.

Public opinion surveys give conflicting results, depending upon the exact questions asked. It would appear that a significant majority of adults in the US and Canada agree that a woman should have free access to a safe abortion in at least the first trimester.