I. A person is guilty of a class A felony if he:
(a) Purposely causes serious bodily injury to another; or
(b) Purposely or knowingly causes bodily injury to another by means of a deadly weapon, except that if the deadly weapon is a firearm, he shall be sentenced in accordance with RSA 651:2, II-g; or
(c) Purposely or knowingly causes injury to another resulting in miscarriage or stillbirth; or
(d) Knowingly or recklessly causes serious bodily injury to a person under 13 years of age.
II. In this section:
(a) "Miscarriage'' means the interruption of the normal development of the fetus other than by a live birth and not an induced abortion, resulting in the complete expulsion or extraction of a fetus; and
(b) "Stillbirth'' means the death of a fetus prior to complete expulsion or extraction and not an induced abortion.