The histopathological effects of superovulatory drugs GnRHα/PMSG/HCG on the endometrial tissues of rat

Background: Using of stimulatory drugs such as: GnRHα/ PMSG/ HCG for induction of superovulation and harvesting more oocytes is very common during Assisted Reproductive Techniques (ART). Studies and experiences have recently shown that the rate of successful implantation in stimulatory cycles is less than natural cycles. Methods: The possible effects of above mentioned drugs on ultrastructures of endometrial tissues (Luminal epithelium) was done by endometrial biopsies from female rats (N=30) which were under superovulaion treatment and from control rats with normal menstrual cycles (N=30). The specimens were processed for electronmicroscopic studies. Qualitative and quantitative (morphologic and morphometric) studies were carried out on electronmicrographs. Morphological findings based on three structures namely: nuclear channel system (NCS), giant mitochondria (GM) and glycogen vacuoles in addition to pinopode system and nuclear euchromatin were evaluated. Results: In morphology, luminal epithelium was more active and had more secretions in rats under superovulation compared with control group. Morphometric findings showed that in case group, volume fraction of nucleus RER, mitochondrium, glycogen to cell and euchromatin to nucleus had statistically significant difference. Conclusion: Superovulatory drugs GnRHα/PMSG/HCG have a negative effect on endometrial tissues at the time of implantation which may lead to low implantation rate.