Many women do abort on the basis of what they consider to be a bad prenatal diagnosis. I know of one. Please think of them when you read this article, because they are highly likely to already be conflicted over their decision, and this is a very hard thing to read:
A report from Beth Daley at the New England Center for Investigative Reporting explores the story of a Rhode Island woman named Stacie Chapman, who very nearly terminated a much-wanted pregnancy at three months after a prenatal blood test called MaterniT21 predicted that her baby probably had Trisomy 18, also known as Edwards Syndrome, a serious chromosomal disorder that can lead to severe birth defects. (The median lifespan for a baby with Edwards is 15 days, and many die long before that.)
Chapman called her husband sobbing when she heard the news, then scheduled an abortion for the following day. Her doctor urged her to wait, and a follow-up test showed that her baby didn’t in fact have Edwards; her son Lincoln Samuel just turned 1 and is perfectly healthy.