18 Pa.C.S. § 108: Time limitations.

(a) General rule.--Except as set forth in subsection (b), a prosecution for any offense under this title must be commenced within the period, if any, limited by Chapter 55 of Title 42 (relating to limitation of time).

(b) Offenses against unborn child.--

(1) A prosecution for criminal homicide of an unborn child may be commenced at any time.

(2) A prosecution for an offense under section 2606 (relating to aggravated assault of unborn child) must be commenced within five years after it is committed.