title: Women's age and embryo developmental speed accurately predict clinical pregnancy after single vitrified-warmed blastocyst transfer.
abstract: The aim of this study was to establish a simple, objective blastocyst grading system using women's age and embryo developmental speed to predict clinical pregnancy after single vitrified-warmed blastocyst transfer. A 6-year retrospective cohort study was conducted in a private infertility centre. A total of 7341 single vitrified-armed blastocyst transfer cycles were included, divided into those carried out between 2006 and 2011 (6046 cycles) and 2012 (1295 cycles). Clinical pregnancy rate, ongoing pregnancy rate and delivery rates were stratified by women's age (<35, 35-37, 38-39, 40-41, 42-45 years) and time to blastocyst expansion (<120, 120-129, 130-139, 140-149, >149 h) as embryo developmental speed. In all the age groups, clinical pregnancy rate, ongoing pregnancy rate and delivery rates decreased as the embryo developmental speed decreased (P < 0.0001). A simple five-grade score based on women's age and embryo developmental speed was determined by actual clinical pregnancy rates observed in the 2006-2011 cohort. Subsequently, the novel grading score was validated in the 2012 cohort (1295 cycles), finding an excellent association. In conclusion, we established a novel blastocyst grading system using women's age and embryo developmental speed as objective parameters.
authors.affiliation: Kato Ladies Clinic, 7-20-3, Nishi-shinjuku, Shinjuku, Tokyo 160-0023, Japan;; Department of Obsterics and Gynecology, Kanazawa University Graduate School of Medicine, 13-1, Takaramachi, Kanazawa, Ishikawa 920-8641, Japan;. Electronic address: k-kato@towako.net.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kato
authors.affiliation: Kato Ladies Clinic, 7-20-3, Nishi-shinjuku, Shinjuku, Tokyo 160-0023, Japan;
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ueno
authors.affiliation: Kato Ladies Clinic, 7-20-3, Nishi-shinjuku, Shinjuku, Tokyo 160-0023, Japan;
authors.forename: Akiko
authors.initials: A
authors.lastname: Yabuuchi
authors.affiliation: Kato Ladies Clinic, 7-20-3, Nishi-shinjuku, Shinjuku, Tokyo 160-0023, Japan;
authors.forename: Kazuo
authors.initials: K
authors.lastname: Uchiyama
authors.affiliation: Kato Ladies Clinic, 7-20-3, Nishi-shinjuku, Shinjuku, Tokyo 160-0023, Japan;
authors.forename: Takashi
authors.initials: T
authors.lastname: Okuno
authors.affiliation: Kato Ladies Clinic, 7-20-3, Nishi-shinjuku, Shinjuku, Tokyo 160-0023, Japan;
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Shinbashi Yume Clinic, 2-5-1, Shinbashi, Minatoku, Tokyo 105-0004, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Segawa
authors.affiliation: Shinbashi Yume Clinic, 2-5-1, Shinbashi, Minatoku, Tokyo 105-0004, Japan.
authors.forename: Shokichi
authors.initials: S
authors.lastname: Teramoto
mesh_terms: D000328:Adult; D000367:Age Factors; D001755:Blastocyst; D015331:Cohort Studies; D015925:Cryopreservation; D004477:Ectogenesis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007247:Infertility, Female / Q000175:diagnosis / Q000628:therapy*; D007564:Japan / Q000453:epidemiology; D050498:Live Birth; D008875:Middle Aged; D011247:Pregnancy; D011255:Pregnancy Maintenance; D018873:Pregnancy Rate; D011379:Prognosis; D012189:Retrospective Studies; D056826:Single Embryo Transfer; D020554:Sperm Injections, Intracytoplasmic; D013997:Time Factors; D058989:Vitrification
keywords: blastocyst culture; in-vitro fertilization; minimal ovarian stimulation; outcome prediction; single embryo transfer