(1) Parental leave received under RCW 41.04.665 must be used within the sixteen weeks immediately after birth or placement, except as provided in subsection (2) of this section.

(2) If a person receiving parental leave also receives leave due to a pregnancy disability, the parental leave may be taken in the sixteen weeks immediately after the pregnancy disability leave. However, parental leave may not be used more than one year after birth.