Endometrial Mucin-1 and Pinopode in Peri-implantation Phase in Ovarian High Responders during Controlled Ovarian Hyperstimulation Cycles

ObjectiveTo investigate effects of ovarian high response on endometrial mucin-1 (MUC1) and pinopode in peri-implantation phase in controlled ovarian hyperstimulation (COH) cycles.MethodsOvarian high response was defined as serum E2 > 15 000 pmol/L on the day of hCG administration in COH cycle using GnRH agonist and recombinant FSH (n=8). Healthy and fertile women were used as the natural control (n=10). Endometrial biopsies were performed on the day of LH+7/hCG+7. Pinopode formation was observed by scanning electron microscope. Expression of MUC1 was detected with quantitative Real-time PCR and immunohistochemistry.ResultsIn high response group, the lumen surface was covered with variant pinopodes and microvillous. The expression of MUC1 mRNA in high response group was lower than that in the natural control (P < 0.05). Immunostaining for MUC1 protein in glandular and luminal epithelium in high response group was lower than that in the natural control (P < 0.05).ConclusionAsynchronized pinopode appearance and lower expression of MUC1 during peri-implantation period were the characteristics of endometrium in high response group, which may provide a clue of decreased endometrial receptivity in the supraphysiological hormone milieu.