DOES TRIGGER DAY PROGESTERONE AFFECT THE OUTCOME OF SUBSEQUENT FROZEN EMBRYO TRANSFER?.

To investigate the effect of progesterone level measured at trigger day on subsequent frozen embryo transfer cycle. Retrospective cohort study. The medical records of 123 women who underwent in vitro fertilization (IVF) without fresh embryo transfer were reviewed. Patients were divided in two groups, women with elevated progesterone (EP, ≥1.5ng/mL) on trigger day (n=26) and women with other reasons of elective cryopreservation (n=97), such as usage of letrozole, risk of ovarian hyperstimulation syndrome, and poor endometrium condition, etc. The outcome of first frozen embryo transfer was investigated. Mann-Whitney test and Fisher’s exact test were used for statistical analysis. Age, BMI, AMH, basal FSH, and initial antral follicle count (AFC) were similar between two groups. Stimulation days were significantly longer in EP group (10.23 vs. 8.73, p=0.004), and total gonadotropin dose was also higher in EP group (3181.73 vs. 2235.05, p=0.002). The outcomes of COS, such as fertilization rate, and the number of oocytes retrieved, mature oocyte, good embryo, and blastocyst, did not differ between two groups. Clinical pregnancy rate was higher in EP group, but it did not achieve statistical significance (34.6% vs. 17.7%, p=0.062). Miscarriage rate was similar in both groups (EP: 33.3% vs. control: 35.3%, p=0.372). Baseline characteristics did not differ according to progesterone level of trigger day, except stimulation days and total gonadotropin doses. Additionally, the outcome of next frozen embryo transfer cycle was similar, regardless of progesterone level on trigger day.