Eran Zilberberg1, Ramsey Smith2, Dan Nayot2, Jigal Haas3, James Meriano2, Eran Barzilay4, Robert F Casper5. 1. TRIO Fertility, Toronto, Ontario, Canada; Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada. 2. TRIO Fertility, Toronto, Ontario, Canada. 3. IVF Unit, Department of Obstetrics and Gynecology, Chaim Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. 4. Obstetrics and Gynecologic Ultrasound Unit, Department of Obstetrics and Gynecology, Assuta Ashdod, Israel; Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. 5. TRIO Fertility, Toronto, Ontario, Canada; Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada; Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada. Electronic address: casper@lunenfeld.ca.
Abstract
OBJECTIVE: To assess whether the calculated difference in endometrial thickness from the end of the estrogen phase to the day of ET (after 6 days of P in hormonally prepared cycles) is associated with ongoing pregnancy rates in euploid frozen ETs (FETs). DESIGN: An observational cohort study. SETTING: Single tertiary care medical center. PATIENT(S): Ultrasound images from 234 hormonally prepared FET cycles were assessed. All the transfers were elective single ETs of a euploid embryo, post-preimplantation genetic testing for aneuploidy (PGT-A). INTERVENTION(S): Ultrasound measurements of peak endometrial thickness at the end of the estrogen phase and again after 6 days of P at the time of ET. MAIN OUTCOME MEASURE(S): Ongoing pregnancy rate in relation to the delta between endometrial thickness at the end of estrogen phase and at the time of ET. RESULT(S): We calculated the ongoing pregnancy rate in cycles where the endometrial lining decreased (compacted) after addition of P by 5%, 10%, 15%, and 20% and demonstrated a significantly higher pregnancy rate after all rates of compaction of the endometrial lining in comparison with cycles where the endometrial lining did not compact. The ongoing pregnancy rate in this cohort, after compaction of 15% or more, was 51.5%, compared with 30.2% in cycles where the endometrial lining did not compact. CONCLUSION(S): There is a significant correlation between endometrial lining compaction and ongoing pregnancy rate in FET cycles of euploid embryos. These findings help to explain why some euploid embryos may fail to implant.
OBJECTIVE: To assess whether the calculated difference in endometrial thickness from the end of the estrogen phase to the day of ET (after 6 days of P in hormonally prepared cycles) is associated with ongoing pregnancy rates in euploid frozen ETs (FETs). DESIGN: An observational cohort study. SETTING: Single tertiary care medical center. PATIENT(S): Ultrasound images from 234 hormonally prepared FET cycles were assessed. All the transfers were elective single ETs of a euploid embryo, post-preimplantation genetic testing for aneuploidy (PGT-A). INTERVENTION(S): Ultrasound measurements of peak endometrial thickness at the end of the estrogen phase and again after 6 days of P at the time of ET. MAIN OUTCOME MEASURE(S): Ongoing pregnancy rate in relation to the delta between endometrial thickness at the end of estrogen phase and at the time of ET. RESULT(S): We calculated the ongoing pregnancy rate in cycles where the endometrial lining decreased (compacted) after addition of P by 5%, 10%, 15%, and 20% and demonstrated a significantly higher pregnancy rate after all rates of compaction of the endometrial lining in comparison with cycles where the endometrial lining did not compact. The ongoing pregnancy rate in this cohort, after compaction of 15% or more, was 51.5%, compared with 30.2% in cycles where the endometrial lining did not compact. CONCLUSION(S): There is a significant correlation between endometrial lining compaction and ongoing pregnancy rate in FET cycles of euploid embryos. These findings help to explain why some euploid embryos may fail to implant.