RU 486 is an artificial steroid that interferes with the action of progesterone, a hormone crucial to the early progress of pregnancy. Progesterone stimulates the proliferation of the uterine lining which nourishes the developing child. It also suppresses normal uterine contractions which could dislodge the child implanted and growing on the wall of the mother's womb.
RU 486 fills the chemical receptor sites normally reserved for progesterone, but does not transmit the progesterone signal. Failing to receive that signal, a woman's body shuts down the preparation of the uterus and initiates the normal menstrual process. The child, deprived of necessary nutrients, starves to death. The baby detaches and is swept out of the body along with the decayed uterine lining.
Printed with permission from National Right to Life (www.nrlc.org ).