Here's one quote from Reagan's book:
I have often said that when we talk about abortion, we are talking about two lives—the life of the mother and the life of the unborn child. Why else do we call a pregnant woman a mother? I have also said that anyone who doesn’t feel sure whether we are talking about a second human life should clearly give life the benefit of the doubt. If you don’t know whether a body is alive or dead, you would never bury it. I think this consideration itself should be enough for all of us to insist on protecting the unborn.