Yes, the best way to do this is by speaking to the baby momma about letting you be part of the adoption. You have to let her know that you’ve taken an interest in this child and their future. It’s a delicate situation and can get complicated at times but you still need to communicate and be the man she needs even if you’re not together with her anymore. She’ll respect you for that as well as the adopted parents.
Expectant mothers are usually required to make every possible attempt to let the potential birth father of their baby know about the baby and her adoption decision before moving forward. Some guys will give consent and be glad they’re not having to pay for child support for 18 years and have a relationship with a woman they’re no longer involved with. Sometimes, adoptions happen without consent of the father.
Even though you aren’t married, you can still play an active role in the decision making process, getting to know the adoptive parents, and receiving your own updates if you choose.