[Study on mechanism of infertility or sterility caused by uterine septa and reproductive prognosis after hysteroscopic metroplasty].

Objective: To study the mechanism of infertility/sterility caused by uterine septa and the reproductive prognosis after transcervical resection of septum (TCRS).

Methods: One hundred and eleven patients with uterine septum including 34 patients of infertility and 77 patients of sterility were performed on TCRS. The patients were followed up of the reproductive outcomes. The process of pregnancies and deliveries were compared with those of 1548 normal uterine pregnancies. We also studied and compared the pathomorphologic and the micro-structure features between the septum and uterine wall in 30 cases (8 cases with infertility and 22 cases with sterility).

Results: (1) The amount of the endometrium glands on septum was less than that on the uterine wall or endometrium un-synchronous growth between septum and uterine wall was shown in 7 cases of infertility and 13 cases of sterility. The positive index level of estrogen and progestogen receptors on septum was weaker than that on uterine wall. The densities of the smooth muscle cells were thicker and the collagenous fibers were sparser in the base and middle of septum compared with uterine wall (P < 0.05). The amounts of the small arteries in septum were rarer than in uterine wall (P < 0.05). Ultrastructure characters showed glandular epithelium cells distributed irregularly and poor pili on septum in the sterility patients. (2) Sixteen infertility patients became pregnant (47.1%, 16/34) postoperation, which was much higher than pregnancy rate of preoperation (8.8%, 3/34, P < 0.01). In sterility group, the spontaneous abortion rate decreased from 84.1% (180/214) to 29.0% (18/62, P < 0.01), and the mature delivery rate and live birth rate rose from 3.3% (7/214), 0.9% (2/214) to 56.4% (35/62) and 64.5% (40/62) respectively (P < 0.01). (3) There were no differences between TCRS patients and normal uterine pregnant women in complications, and the mortality of perinatal (P > 0.05). The rate of cesarean section in post-TCRS patients was higher than in normal control group (P < 0.01).

Conclusions: The differences of pathomorphology and ultra-structure between septum and uterine wall are the causation of infertility/sterility in the uterine septum patients. The reproductive prognosis can be improved remarkably by performing TCRS, which does not increase pregnant complications or affect fetus growth. Cesarean section should not be a standard way for delivery.