First, it is CRITICAL to note that the claims of prolife about rape-pregnancies is BASED UPON ABORTION BEING LEGAL. Since they want abortions made illegal, their claim of rape-pregnancies is pointless OTHER THAN THEY WANT LOTS MORE OF THEM.
Second, few women will claim her pregnancy was by rape. In fact, if she is carrying the pregnancy to full term she would be a ROTTEN mother if she did decided to put that label on the child for that child's whole life - and a fool to put that label on herself. You only have to look at messages posted on this forum by many men on sexual assault to understand why. Plus doing so would add the horrific legal risks of the rapist claiming parental rights and visitation - meaning the rapist is in her life for decades.