OBJECTIVE: To compare implantation and pregnancy rates according to the day of embryo transfer (day 5 or 6 after oocyte retrieval) when transfer was postponed until expanded blastocysts developed. DESIGN: Retrospective clinical study. SETTING: Private ART center. PATIENT(S): One-hundred and eighty-three women undergoing blastocyst-stage embryo transfer following in vitro fertilization. INTERVENTION(S): Bipronucleate oocytes were grown for up to 144 hours and subsequently transferred only when at least one embryo attained the expanded blastocyst stage. MAIN OUTCOME MEASURE(S): Implantation and pregnancy rates. RESULT(S): Blastocysts transferred on day 5 implanted at nearly twice the rate of blastocysts transferred on day 6 (36.3% vs. 19.0%). Pregnancy rates were also almost twice as high among the day 5 transfer patients (59.3% vs. 32.3%). In addition, more blastocysts developed (3.6 vs. 2.4), and more were transferred (2.7 vs. 2.3) to the day 5 transfer patients, although the proportion of expanded blastocysts among the blastocysts that were transferred was the same for the two groups (91.7% vs. 93.6%). CONCLUSION(S): Embryos that develop to the expanded blastocyst stage and are transferred on day 5 after retrieval are approximately twice as likely to implant compared to those for which expansion and transfer are delayed until day 6.
OBJECTIVE: To compare implantation and pregnancy rates according to the day of embryo transfer (day 5 or 6 after oocyte retrieval) when transfer was postponed until expanded blastocysts developed. DESIGN: Retrospective clinical study. SETTING: Private ART center. PATIENT(S): One-hundred and eighty-three women undergoing blastocyst-stage embryo transfer following in vitro fertilization. INTERVENTION(S): Bipronucleate oocytes were grown for up to 144 hours and subsequently transferred only when at least one embryo attained the expanded blastocyst stage. MAIN OUTCOME MEASURE(S): Implantation and pregnancy rates. RESULT(S): Blastocysts transferred on day 5 implanted at nearly twice the rate of blastocysts transferred on day 6 (36.3% vs. 19.0%). Pregnancy rates were also almost twice as high among the day 5 transfer patients (59.3% vs. 32.3%). In addition, more blastocysts developed (3.6 vs. 2.4), and more were transferred (2.7 vs. 2.3) to the day 5 transfer patients, although the proportion of expanded blastocysts among the blastocysts that were transferred was the same for the two groups (91.7% vs. 93.6%). CONCLUSION(S): Embryos that develop to the expanded blastocyst stage and are transferred on day 5 after retrieval are approximately twice as likely to implant compared to those for which expansion and transfer are delayed until day 6.
Authors: Mae Wu Healy; Meghan Yamasaki; George Patounakis; Kevin S Richter; Kate Devine; Alan H DeCherney; Micah J Hill Journal: Hum Reprod Date: 2016-12-16 Impact factor: 6.918
Authors: Jonathan D Kort; Ruth B Lathi; Kathleen Brookfield; Valerie L Baker; Qianying Zhao; Barry R Behr Journal: J Assist Reprod Genet Date: 2015-04-29 Impact factor: 3.412
Authors: Oleksii O Barash; Kristen A Ivani; Susan P Willman; Evan M Rosenbluth; Deborah S Wachs; Mary D Hinckley; Sara Pittenger Reid; Louis N Weckstein Journal: J Assist Reprod Genet Date: 2017-05-30 Impact factor: 3.412
Authors: Sang Min Kang; Sang Won Lee; San Hyun Yoon; Joo Cheol Kim; Jin Ho Lim; Seong Goo Lee Journal: J Assist Reprod Genet Date: 2013-05-30 Impact factor: 3.412