First of all, those are not "children", they are either "fetuses" or "unborn babies".
Second of all, they believe that life begins at conception, therefore abortion at any week is wrong.
Third of all, I've had healthy debates with them about abortion but it usually ended up with them not wanting to talk about it anymore so we just leave it at that. Apparently the issue is very emotional for them.
And apparently you ignored the fact that I was pro-life for many years and those were THE SAME FRIENDS as today.