Advice about dealing with my mom

My parents adopted me when I was a toddler because they couldn't have children. Every time my own pregnancy comes up, especially if I'm confused or express that I don't know something, my mom makes resentful comments about not having been able to have kids. She becomes crabby and doesn't really want to talk about my pregnancy anymore. Should I just give up on being so excited around my mom or should I keep trying to include her? She's my mom and I want her included, but it's that fair to her?