P-651 Neither high nor low serum progesterone levels affect clinical outcomes in Artificially prepared-frozen embryo transfer cycles using intramuscular progesterone

Abstract

Abstract Study question Does serum progesterone level on the day of frozen-thawed embryo-transfer (FET) correlate with the likelihood of achieving pregnancy in artificial FET cycles utilizing intramuscular progesterone? Summary answer Serum progesterone levels on the day of FET do not correlate with the likelihood of achieving a pregnancy in artificial FET cycles employing intramuscular progesterone. What is known already There is scientific evidence suggesting that serum progesterone levels under a specific cutoff level on the day of FET significantly decrease the clinical outcomes in patients under artificial endometrial preparation using micronized vaginal progesterone. However, no substantial evidence exists in patients under artificial endometrial preparation using intramuscular progesterone. Study design, size, duration This prospective cohort study was conducted from February to December 2022 and enrolled 353 patients undergoing FET in hormone replacement therapy (HRT) cycles using intramuscular progesterone until the day of embryo transfer. Participants/materials, setting, methods The study included women aged 21-40 years old undergoing FET, triple layer endometrium >7mm, and ≥2 high-quality embryos (Gardner’s grade 3/4/5/AA/AB/BA/BB) available. Exclusion criteria included patients with uncontrolled diabetes, hypertension, heart disease, known autoimmune diseases, uterine infertility factor, severe male factor infertility (total sperm count < 5 million/ml), and cases requiring surgically retrieved sperm for ICSI. Main results and the role of chance The cohort had an average age of 32.09 ± 4.19 years, BMI of 24.70 ± 3.07 kg/m², and endometrial thickness of 8.87 ± 1.06 mm on the day of embryo transfer. The mean serum progesterone level was 31.36 ± 13.78 ng/ml. Participants were categorized into quartiles based on serum progesterone levels. :Q1 (<21.7 ng/ml), Q2 (21.7-28.1 ng/ml), Q3 (28.2-40.0 ng/ml), and Q4 (≥40.0 ng/ml). No significant difference in Clinical Pregnancy Rate (CPR), Ongoing Pregnancy Rates (OPR), and first-trimester miscarriage rates were observed across quartiles. The OPRs according to serum progesterone quartiles were: Q1: 57.5%; Q2: 62.6%; Q3: 59.6%; Q4:62.8%, with no statistical difference among the groups. Binary logistic regression revealed no statistically significant differences in clinical pregnancy and ongoing odds among the quartiles. Limitations, reasons for caution Although a prospective study, its relatively small sample size may affect the results’ robustness and generalizability. Wider implications of the findings These findings suggest that when using intramuscular progesterone before embryo transfer in FET under HRT, serum progesterone testing may not be necessary before embryo transfer, as progesterone levels have no impact on clinical outcomes in this group of patients. Trial registration number CTRI/2022/11/046995