There are not enough parents who want them- that is why you see so many black children in foster care, even babies. Most white couples would rather adopt internationally than bring a American black child home...not because of racism, per se, but because they want children who look like them, or as close as possible.
Of course it is better to not be aborted, but let's not pretend that there are willing parents for each child that would be saved if abortion were criminalized.