Abstract：
This study aimed to determine whether the use of vaginal Endometrin plus intramuscular progesterone on every third day (VIM) in programmed frozen embryo transfer (FET) is associated with lower pregnancy and live birth rates compared to daily intramuscular progesterone (IM). FET data from a single program were collected between November 2018 and December 2021. A total of 903 FETs were analyzed, including 504 FETs in the IM group, and 399 FETs in the VIM group. Inclusion criteria were women undergoing FETs with either 50 mg daily IM progesterone only (control) or 200 mg Endometrin twice daily plus 50 mg IM progesterone on every third day, with the transfer of a single day 5 or 6 frozen embryo. There were no significant differences in patient age at time of FETs, BMI, endometrial thickness, blastocyst quality, or infertility diagnosis between the groups. The VIM had significantly lower positive hCG and clinical pregnancy rates compared to the IM (60.2% vs 72.0% and 40.6% vs 56.7%, respectively, P = 0.0002 and P < 0.0001). The live birth rate was 36.1% in the VIM, compared to 49.4% in the IM (P < 0.0001). These findings also remained significant when excluding FETs with donor egg (35.9% vs 50.1%, P < 0.0001). This study demonstrated that VIM in FET cycles yields significantly lower pregnancy and live birth rates compared to IM along. IM progesterone alone may be preferable to combined Endometrin and IM progesterone in patients undergoing programmed frozen embryo transfers.
摘要：
这项研究旨在确定与每日肌内孕酮（IM）相比，在程序化冷冻胚胎移植（FET）中每三天使用阴道Endometin加肌内孕酮（VIM）是否与较低的妊娠和活产率相关。单一项目的FET数据是在2018年11月至2021年12月之间收集的。总共分析了903个FET，包括IM组中的504个FET，VIM组中的399个FET。纳入标准是接受FET的女性，每天仅50mgIM孕酮（对照）或每天两次200mgEndometry，每三天一次加上50mgIM孕酮。与转移一个单一的一天5或6冷冻胚胎。在使用FET时，患者年龄没有显着差异，BMI,子宫内膜厚度,囊胚质量,或组间不孕症诊断。与IM相比，VIM的hCG阳性和临床妊娠率显着降低（60.2％vs72.0％和40.6％vs56.7％，分别,P=0.0002和P<0.0001)。VIM的活产率为36.1%,与IM的49.4%相比（P<0.0001）。当排除带有供体卵的FET时，这些发现也仍然显着（35.9%vs50.1%，P<0.0001)。这项研究表明，与IM相比，FET周期中的VIM产生的妊娠和活产率显着降低。在接受程序化冷冻胚胎移植的患者中，单独使用IM孕酮可能优于Endometin和IM孕酮的组合。
