EFFECT OF AN INTRAUTERINE DEVICE ON MENSTRUAL CYCLICITY AND LUTEAL FUNCTION IN THE BABOON

Abstract

Summary. In the baboon, the presence of an IUD slightly shortens the length of the menstrual cycle and prolongs that of menstruation. Sexual skin changes showed that the part of the cycle shortened was the detumescent (= secretory) phase, the tumescent (= proliferative) phase remaining unaffected. Plasma progesterone levels during the latter half of the cycle were not affected by the IUD, but the onset of menstruation in experimental animals was associated with a higher blood concentration of progesterone than that present in controls. It is concluded that an IUD does not interfere with luteal function in the baboon.