title: Comparison of aneuploidy, pregnancy and live birth rates between day 5 and day 6 blastocysts.
abstract: Comprehensive chromosome screening is typically used for aneuploidy analysis of blastocysts. It is believed that either day of blastocyst development is acceptable. Euploidy rates and outcomes were examined between day 5 and day 6 blastocysts in two studies. First, euploidy rates of day 5 and day 6 blastocysts were examined on a per-embryo and per-patient basis. Second, outcomes were compared when only euploid day 5 or day 6 blastocysts were transferred in a cryopreserved embryo transfer cycle. In cycles (n = 70) that had blastocysts biopsied on both day 5 and day 6, day 5 blastocysts had a higher chance of being euploid than day 6 blastocysts (125/229 [54.6%]) and (77/180 [42.8%]), respectively (P = 0.0231). Similarly, euploid rates in blastocysts from patients (n = 193) with day 5 biopsy, day 6 biopsy, or both, were significantly higher in day 5 (235/421 [55.8%]) compared with day 6 (184/413 [44.6%]) blastocysts (P = 0.0014). In the second study, 50 women (36.1 ± 4.3 years) and 39 women (35.1 ± 3.8 years) with only euploid day 5 or euploid day 6 blastocysts transferred during a cryopreserved embryo transfer had similar cycle outcomes. Although underpowered, these data suggest that euploid day 6 blastocysts are as capable of positive outcomes as their euploid day 5 counterparts.
authors.affiliation: Reproductive Endocrinology Associates of Charlotte, 1524 E. Morehead Street, Charlotte, NC 28207, USA; Department of Biosciences, University of Kent, Canterbury CT2 7NJ, UK.
authors.forename: Tyl H
authors.initials: TH
authors.lastname: Taylor
authors.affiliation: Reproductive Endocrinology Associates of Charlotte, 1524 E. Morehead Street, Charlotte, NC 28207, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Patrick
authors.affiliation: Department of Obstetrics and Gynecology, Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, 601 Colley Avenue #316, Norfolk, VA 23507, USA.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Gitlin
authors.affiliation: Reproductive Endocrinology Associates of Charlotte, 1524 E. Morehead Street, Charlotte, NC 28207, USA.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Wilson
authors.affiliation: Reproductive Endocrinology Associates of Charlotte, 1524 E. Morehead Street, Charlotte, NC 28207, USA.
authors.forename: Jack L
authors.initials: JL
authors.lastname: Crain
authors.affiliation: Department of Biosciences, University of Kent, Canterbury CT2 7NJ, UK. Electronic address: d.k.griffin@kent.ac.uk.
authors.forename: Darren K
authors.initials: DK
authors.lastname: Griffin
mesh_terms: D000328:Adult; D000782:Aneuploidy; D001723:Birth Rate; D001755:Blastocyst / Q000502:physiology*; D010064:Embryo Implantation / Q000502:physiology*; D004624:Embryo Transfer; D005260:Female; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate
keywords: IVF; aneuploidy; blastocyst; cryopreserved embryo transfer