Objective: To determine the expression and location of estrogen and progesterone receptor isoforms in the endometrium after abortion and discuss the relationship between the changes of isoforms and prolonged uterine bleeding after medical abortion.
Methods: 45 endometrium biopsy were obtained from 15 women with prolonged bleeding after medical abortion, 15 women with prolonged bleeding after vacuum aspiration and 15 without prolonged bleeding after vacuum aspiration as control group. Immunohistochemical staining intensity of ER alpha, ER beta, PR-A and PR-B in endometrium were compared among these groups, as medical abortion group, surgical abortion group and control group.
Results: The endometrial ER alpha, ER beta, PR-A and PR-B H-Scores of medical abortion group were 166.7 (88.5), 161.5 (84), 180.0 (109) and 136.5 (119.0), The endometrial ER alpha, ER beta, PR-A and PR-B H-Scores of control group were 306.7 (45.9), 230.0 (75.0), 224.2 (57) and 389.6 (106.6). The endometrial ER alpha, ER beta, PR-A and PR-B H-Scores of surgical abortion group were 109.4 (114.6), 225.0 (120.0), 175.5 (225) and 50.0 (89.0). The endometrial ER alpha, ER beta, PR-B H-Scores of medical abortion group were significantly lower than those of control group. And in surgical abortion group ER alpha and PR-B H-Scores were significantly lower than those in control group. But there was no significant difference between ER beta H-Scores of surgical abortion group and control group. There were no significant differences of ER and PR isoforms level ratios of endometrial glands to endometrial stroma among three groups.
Conclusions: The decreased ER alpha, ER beta and PR-B levels in the human endometrium may be related to prolonged uterine bleeding after medical abortion by mifepristone accompanied with misopristol. The endometrial ER alpha, PR-B decreased in women after vacuum aspiration abortion may be related to abnormal prolonged uterine bleeding. The changes of endometrial ER, PR isoforms in glands and stroma were simultaneous after medical abortion and surgical abortion.