Significance of endometrial stripe thickness (EST) in programmed frozen thawed blastocyst transfer outcomes

While previous studies linking EST and transfer outcomes have focused on the transfer of cleavage stage embryos, we wished to examine the relationship between EST and the outcomes of medicated frozen-thawed blastocyst (BL) transfer cycles. Retrospective cohort study. All consecutive patients who underwent programmed medicated fresh embryo transfer (PFET) cycles over an eight-year period were reviewed. The EST of patients undergoing PFET were analyzed by quintiles and comparisons were made among the lowest, middle three and highest quintiles. Two-tailed t-tests were used to compare individual groups. P<0.05 was considered statistically significant. In the lowest quintile (EST ≤ 7.9 mm), implantation and clinical pregnancy rates were lower than patients with EST ≥ 8mm.Tabled 1Lowest quintile (EST ≤ 7.9mm)Middle three quintiles (EST 8-11.7mm)Highest quintile (EST ≥ 11.8mm)P (1 vs. 2)P (1 vs. 3)P (2 vs. 3)N189528178N/AN/AN/AMean age (yrs)38.5 (±6.3)38.2 (±6.0)37.2 (±6.8)NSNSNSMean E2 (pg/ml)794.1 (±422.0)735.1 (±392.3)731.6 (±445.2)NSNSNSSurvival rate (%)89.4987.7888.2NSNSNS# BL trans.1.79 (±0.75)1.70 (±0.71)1.71 (±0.74)NSNSNSImp. rate (%)17.425.227.60.020.02NSClin. preg. rate (%)31.240.647.20.020.001NS Open table in a new tab Our study shows that EST of less than 8 mm on the day of progesterone supplementation is associated with lower implantation and clinical pregnancy rates.