Characteristics of short protocol in fresh ET cycles and effect on pregnancy outcomes
The advantages of short protocol could promote the secretion of FSH by flare-up effect, strengthen the recruitment of early follicles, improve the response of ovaries, and avoid the over-inhibition of long acting GnRHa. Compared with ultra-long and long protocols, CPR and LBR were significantly decreased. Vice versa, compared with antagonist protocol, there were no statistical differences on IR, CPR, MR, and LBR. Sheng compared pregnancy outcomes of ultralong, long and short protocols, and the CPR in short protocol was 22.4%(17), which was similar with our data. Short and antagonist protocols could not induce hypo-estrogenism and recover potential endometrial normalization of adenomyosis(18, 19), so when they were used, fresh ET should be prudent because of the obviously negative pregnancy outcomes.