Some years ago, I read about some research about why women get late term abortions (I think definition was something like 20+ weeks gestation).
I recall the first two reasons.
The most common reason cited was women who did not know they were pregnant (fat women with irregular cycles, I guess). I actually went to high school with a guy whose wife supposedly didn't know she was pregnant until she went into labor. That was the rumor anyway.
The second most common reason for having a late term abortion cited was women who procrastinated getting an abortion.
I oppose elective abortions at any age. The ones at later ages get me angrier though, as it is easier for me to identify with the baby, and those killing them have no real excuse that they don't realize what they are doing.