I really don't know. There are so many laws regarding juveniles I'm just not sure. And they also vary by state. Some states require that the parents of underage girls must be notified of an abortion. In that case, I think they would find out pretty quickly who got her pregnant and justice would follow its course.
I know that as a physician you have to notify the authorities if you suspect child abuse. So I don't know why it would be different for sexual abuse/underage rape. (I know that adults have the option to press charges or not.) But I'm not sure about consensual statuatory rape. There are just so many variables.
The difference between reporting child abuse and statutory rape is clear when you have the proper information.
Child abuse is done (or facilitated) by a parent or guardian, i.e. the one with legal authority over the child. If I hit my kid, it's child abuse (reportable) and the
family court gets involved, and I might lose custody. The punishment is very rarely any kind of jail time, but rather I lose my rights/access to the child. (Contrast this with what happens if I hit
your kid - it's assault, the
criminal court gets involved, and I go to jail.)
Rape, whether forcible or "statutory", is not reportable by third parties, out of respect for the victims (and in recognition of the grueling process involved for them). It does not involve the investigation and/or reconsideration of parental rights. The criminal court is involved, not the family court. The punishment involved is jail time, not loss of rights/access. You can't report the 14-year-old who has a 20-year-old boyfriend to the police,
without her consent, any more than you can do so for the college girl who got roofied. You can, in both cases, counsel intensively and try to get them to tell their folks and/or press charges. But if they won't, they won't. And you can't tell the parents either, against the patient's wishes - confidentiality.
The exception is when the execution of the statutory rape involves the parents/guardians; e.g. the mother knowingly allows her boyfriend to sleep with her kid. Then, it is reportable because the legal rights of the parent are brought into question and the situation must be investigated for that purpose (mandatory reporting exists because parental abuse/neglect is visible
only to "care workers" usually, and not the public at large).
It's also interesting to note that most states that require parental notification of an abortion do so
regardless of whether the pregnancy is the result of abuse or incest - a 13-year-old in Idaho, Spring Adams, was forced to tell her incesting dad that she was pregnant by him and wanted an abortion. He realized that the secret would probably come out at the clinic, so before she went for her appointment (there's always a waiting period attached to the notification), he killed her with a shotgun as she slept.
I don't like parental notification laws. Even in families where "things work out as they should", i.e. parents are supportive of the kid but throw the guy in jail, the outcome is bad - you are just creating a "Romeo & Juliet" circumstance (remember, the kid fully consented) where this teen will allow their adolescent rebellion to intensify their bad choices and flawed perspective. When it's the parents vs. the lover, the lover always wins (in the kid's eyes). Especially if he "goes to jail...just for loving you! [swoon]".