Histochemical changes in the endometrium after the use of IUCD and oral contraceptives.

A comparison and evaluation of glycogen and alkaline phosphatase levels in the endometrium produced by the IUD and oral contraceptives (OCs) was undertaken to illuminate the mechanism of action of these 2 methods of contraception. Over a 2 year period 260 cases were studied: 120 cases used IUD-CuT 100 subjects used OCs and 40 women served as controls. Endometrial glycogen content was assessed using PAS stain. Alkaline phosphatase normally present in uterine secretions was assessed by the Naphethal AS-MX phosphatase method. All cases were studied during phases of the menstrual cycle. Results indicated a uniform decrease of endometrial glycogen in all cases of IUD and OC users as compared to controls and slightly more of a decrease in the IUD cases compared to the OC users although not a significant difference. A suggested mode of action of OCs and the IUD is endometrial glycopenia which deprives the blastocyst of necessary glucose during the preimplantation stage. Alkaline phosphatase activity was not altered in 60% of the IUD cases; the remaining 40% showed a decrease in activity during the secretory phase. With OCs alkaline phosphatase activity was inhibited in the proliferative phase but increased during the secretory phase. Increases in alkaline phosphatase in the secretory phase denotes poor progesterone activity and suggests a probable basis of the OCs action.