You can’t force someone or bully them into having an abortion. The best thing is to take responsibility and don’t be the guy that doesn’t stand up and be the man that you should be. Focus on the well-being of the child and realize the child needs to be raised in a stable environment, which can be done through an open adoption. You shouldn’t block an adoption if that is what she wants.
Listen to her like you haven’t before. Women like to talk things out, while men like to shut things out. You might be at maximum stress and most men when they feel stressed about work, about money, about the relationship, will turn inward. This will only provoke more stress and create more stress for the baby mama which isn’t good for anyone. She will have a feeling of being alone, a fear of abandonment and rejection. She is going through enough with hormones, the pregnancy and having to put together an adoption.
It is important to not blame her for the pregnancy. It takes two. Try to show her some respect as you take responsibility for the life you created together. It’s easier to get along with someone that respects you. Respect her for being the mother of this child and wanting to do what is best. You can really come out as a good guy if you do.