Statutory rape differs from forcible rape in that statutory rape does not involve force or threats. For instance, if a girl is 15 and has sex with a guy who is 26, that is statutory rape, even though both parties are perfectly willing and nobody is traumatized (except maybe her parents and a few million religious fundamentalists). So no, statutory rape is not forced. The reason it's a crime is because society wants to protect those below the age of consent from older people who might want to prey on them sexually, seduce or coerce them into sex when they are not old enough to be considered able to consent lawfully. Thus it's "statutory," that is, defined by statute or law.

The anti-abortion folks are trying to separate out the people who willingly have sex from those who do so against their will, and then punish the former if they get pregnant. It's perfectly illogical IMO. Either the baby deserves the right to life or it doesn't. The behavior of its parents shouldn't be part of the equation.