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Blastocyst embryo transfer is the primary determinant for improved outcomes in oocyte donation cycles
Author(s) -
Porat Natalie,
Boehnlein Lynn M.,
Barker Matthew A.,
Kovacs Peter,
Lindheim Steven R.
Publication year - 2010
Publication title -
journal of obstetrics and gynaecology research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 50
eISSN - 1447-0756
pISSN - 1341-8076
DOI - 10.1111/j.1447-0756.2009.01135.x
Subject(s) - blastocyst , medicine , embryo , andrology , embryo transfer , blastocyst transfer , gynecology , pregnancy rate , pregnancy , oocyte , oocyte donation , embryo quality , in vitro fertilisation , embryogenesis , biology , genetics
Aim: Using oocyte donation cycles as an ideal model, we sought to compare pregnancy and implantation rates in cleavage stage (day 3) versus blastocyst stage (day 6) embryo transfers (ET); assess the predictive value of blastocyst formation rates based on cleavage cell stage and morphology grade; and evaluate the ability to predict formation of high quality (HQ) blastocysts. Methods: Ninety three consecutive oocyte donation cycles from July 2003 to August 2005 were retrospectively evaluated and analyzed to determine if either resulted in a cleavage stage ( n = 30) or blastocyst ( n = 45) ET. The primary outcomes measured pregnancy rates, the percent development of HQ blastocysts based on day 3 embryo status, and the ability to select day 3 embryos suitable for transfer among four blinded evaluators by assessing their day 6 embryo outcome. Results: Cleavage stage ET resulted in significantly lower pregnancy rates, clinical pregnancy rates, and implantation rates (47% [ n = 14/30]; 40% [ n = 12/30] and 27 ± 7%) compared to blastocyst stage (82% [ n = 37/45]; 73% [ n = 33/45] and 64 ± 6% [±SE], P < 0.01). In total, HQ blastocysts resulted from high and good quality day 3 embryos 35% (191/546) and 17% (93/546), respectively. Blinded evaluation revealed at least one, two or all three day 3 embryos were correctly selected for ET on day 6, 97%, 67% and 19%, respectively. Conclusion: Day 6 ET resulted in significantly better clinical outcomes compared to day 3 ET. While day 3 status is not predictive of blastocyst quality, the selection of at least one day 3 embryo ultimately suitable for blastocyst ET underscores the significance of optimal endometrial receptivity.