The ultrastructural effects of superovulatory drugs on mouse endometrial basement membrane

Abstract Background: The endometrial basement membrane has a major role in implantation of embryo. Studies have recently shown that the rate of successful implantation in stimulatory cycles is less than in normal cycles due to detrimental effect of superovulatory drugs on endometrium. Objective: to investigate the effects of stimulatory drugs on ultrastructures of mouse endometrial basement membrane. Methods: The endometrial samples were obtained from 30 naturally pregnant mice (control group) and 30 superovulated mice (experimental group) at the time of implantation (120 h after hCG injection). Induced with PMSG (10 IU) and hCG (10 IU) The specimens were processed for electron microscopic studies. Qualitative (based on electron density) and quantitative (thickness of basement membrane) studies were performed on micrographs. The data were analyzed using Mann-Whitney statistical test. Findings: The qualitative observation of the case group revealed a well developed RER, increased number of mitochondria and high electron density of basement membrane. The quantitative data demonstrated that the thickness of basement membrane and lamina densa were significantly increased in the case group compared with control group (0.283±0.0777, 0.158±0.00827 vs. 0.239±0.0082, 0.155±0.0111, P<0.05). Conclusion: It can be concluded that superovulation drugs may lead to low implantation rate by changing the endometrial basement membrane.