You could have googled that. The reason is medical and has to do with what is best for the woman. Even with a non viable phoetus they would do that.

Anti abortion people is so used to distort language than you no longer are paying attention to the facts. Women who want to abort at 37 have been pregnant the previous 37 weeks. They would only wait so long if they previously wanted the pregnancy and the change is usually because some life threatening condition or a non viable pregnancy. At that point, her health is prioritized and that is the safest procedure for her. So it as nothing to do with the phoetus.

But you keep focusing on the phoetus (since it is the only thing you care about) and ignoring the woman, who is the one pregnant.