THE EFFECT OF UTERINE ANASTOMOSIS ON THE ACTION OF AN INTRA-UTERINE DEVICE IN THE RAT

Abstract

SUMMARY In the rat, when luminal continuity was established between the two uterine horns, a unilateral intra-uterine device (IUD) exerted a complete, bilateral contraceptive effect. This was related to the elimination of blastocysts from both uterine horns and to the bilateral inhibition of the decidual cell reaction. Both uterine horns showed leucocytic infiltration into the endometrium, although infiltration was greater in the IUD horn than in the control horn. When the uterine horns were united without the establishment of luminal continuity a unilateral IUD exerted a strictly unilateral effect, and leucocytic infiltration was only detected in the IUD endometrium and uterine lumen. These results support the view that the environment within the separate or continuous uterine lumina was altered in the presence of an IUD so that the decidual cell response was inhibited and blastocysts were eliminated. The possibility that this change was related to leucocytic infiltration into the endometrium and uterine lumen cannot be eliminated.