LAUSR

The optimal route of progesterone administration for luteal phase support in a frozen embryo transfer: A systematic review Due to the heterogeneity of the results, it was not possible to determine which route had the best outcome. Luteal phase support (LPS) with progesterone is used to optimize outcomes in frozen embryo transfer (FET) cycles, though there is uncertainty about optimal route of progesterone administration. Objective: To systematically review evidence from randomized controlled trials (RCTs) comparing the various routes (oral, vaginal, and intramuscular) of progesterone administration for LPS in women undergoing FETs. In a systematic review of RCTs Medline, Embase, Web of Science and Cochrane controlled trials register were searched without language restrictions from database inception to June 2021. Data were extracted and quality assessed for risk of bias. Individual results were computed as relative risks (RR) with 95% confidence intervals (CI). (Prospective registration, PROSPERO No. CRD4202251017) There were 4 eligible trials including 2790 participants. Risk of bias was low concerning randomization process, but there were concerns with respect to intended interventions, missing data, outcome measurement and selective reporting. Interventions were heterogeneous with respect doses and types of progesterone. Only one study (at high risk of bias) showed a statistically significant result in favour of vaginal vs oral progesterone for clinical pregnancy rates (RR 0.45, 95% CI 0.22-0.92); for other route comparisons, individual results were not statistically significant. The comparison of route of administration of progesterone for LPS needs robust multicentre trials, and advanced data syntheses including indirect comparisons and network meta-analyses in the future. The assessment of progesterone supplemention needs a universal agreed protocol to be implemented in guideline for clincian to follow Not applicable