A lot of people seem to think abortion is just like, flushing a toilet or some stuff, and the mother just suddenly becomes 'not pregnant'. That's not the case. It's can be a very invasive surgery, stuff ain't loving fun, no woman uses abortion as a form of contraception. They use it as a last resort when all other forms of contraception have failed and they are now pregnant with a baby that they cannot raise, or might even kill them. I believe in the right to abort your fetus, up to a certain stage. Once you find out you are pregnant you should make it your top priority to decide whether or not you will birth your child. If you leave it to a certain stage where the fetus is becoming more than just some cells/an egg, it should be assumed that you have made the (legal) decision to birth your child (unless the pregnancy becomes life threatening)
Nobody likes abortion. Realistically, you cannot tell people what to do with their own bodies. If you refuse a desperate woman an abortion, they may take drastic/desperate measures, which will be far less human than a clinical operation.
It should totally be allowed, but the husband should definitely have some say in the matter before the baby is aborted.
This ultimately opens an avenue to abuse. IMO, if the husband wants an abortion and the wife does not, he shouldn't have to pay child support. If he wants the child and she aborts it, he should be compensated. But you can't tell someone whether or not they will give birth.