So now the number of options he has is what decides what's fair and what isn't when it comes to childbearing? That's just completely arbitrary. He can choose not to get a woman pregnant in the first place. When the child is born he can choose to be a father in every sense of the word or just in the financial sense or not even at all because our enforcement is so poor or he can agree to adopt the child out if that's what the mother wants to do or block that from happening if he doesn't want it to happen.
If you want to talk about inequality in childbearing, can we look at the physical for a moment? What happens in a pregnancy can affect a woman for the rest of her life. I've never seen a father lose pints of blood, have a stroke, an embolism, a forced hysterectomy, be placed on weeks of bedrest, lose his job and his income, etc. Even with a healthy pregnancy a father doesn't have his body completely taken over, won't have morning sickness, won't get stretch marks, won't have extremely painful contractions for hours on end, won't have his genitals cut with a pair of scissors, etc.
There is no equality in childbearing. We just have to do the best we can with what we have. Since women have to deal with the physical, they get to decide on abortion and men don't. You think that's unfair, I think that's the only fair way to deal with the fact that men can't carry children. All their other choices are the same.