(k) The terms "because of sex" or "on the basis of sex"
include, but are not limited to, because of or on the basis of
pregnancy, childbirth, or related medical conditions; and women
affected by pregnancy, childbirth, or related medical conditions
shall be treated the same for all employment-related purposes,
including receipt of benefits under fringe benefit programs, as
other persons not so affected but similar in their ability or
inability to work, and nothing in section 2000e-2(h) of this
title shall be interpreted to permit otherwise. This subsection
shall not require an employer to pay for health insurance
benefits for abortion, except where the life of the mother would
be endangered if the fetus were carried to term, or except where
medical complications have arisen from an abortion: Provided,
That nothing herein shall preclude an employer from providing
abortion benefits or otherwise affect bargaining agreements in
regard to abortion.