Single-embryo transfer of vitrified-warmed blastocysts yields equivalent live-birth rates and improved neonatal outcomes compared with fresh transfers

• Published in: Fertility and sterility Vol. 101; no. 5; pp. 1294 - 1301.e2
• Main Authors: Roy, Tammie K., Ph.D, Bradley, Cara K., Ph.D, Bowman, Mark C., M.B.B.S., Ph.D, McArthur, Steven J., B.Sc
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-05-2014
• Subjects: Adult; Assisted reproduction; Blastocyst; Embryo Transfer - methods; Embryo Transfer - trends; Female; Hot Temperature - therapeutic use; human; Humans; Infant, Newborn; Internal Medicine; Obstetrics and Gynecology; Pregnancy; Pregnancy Rate - trends; Retrospective Studies; Single Embryo Transfer - methods; Single Embryo Transfer - trends; single-embryo transfer; Vitrification; blastocyst; Assisted reproduction; human; single-embryo transfer; vitrification
• ISSN: 0015-0282; 1556-5653
• DOI: 10.1016/j.fertnstert.2014.01.046

Objective To compare pregnancy and neonatal outcomes after fresh and vitrified-warmed single-blastocyst transfers. Design Retrospective study. Setting Private in vitro fertilization (IVF) clinic. Patient(s) 1,209 infertile patients who underwent a total of 1,157 fresh and 645 vitrified-warmed embryo transfers. Intervention(s) Day-5 single-blastocyst transfers using fresh or vitrified-warmed (Cryotop method) grade I and grade II embryos. Main Outcome Measure(s) Fetal heart pregnancy rate, live-birth rate, gestational age, and live-birth weight. Result(s) The overall blastocyst thaw survival rate was 94.4% and was not significantly different between blastocyst grades or developmental stages. Similar clinical outcomes were achieved for fresh and vitrified-warmed blastocyst transfers; for example, grade I blastocysts had a live-birth rate of 52.8% versus 55.3%, respectively, and grade II blastocysts had a rate of 34.9% versus 30.4%, respectively. Significantly improved neonatal outcomes were evident for vitrified-warmed blastocyst transfers for gestational age, being on average 0.3 weeks longer, and for live-birth weight with babies born on average 145 g heavier (3,296 g versus 3,441 g for fresh and vitrified-warmed groups, respectively), as compared with fresh transfers. Conclusion(s) Embryo transfer of vitrified-warmed blastocysts yields equivalent live-birth rates and improved neonatal outcomes compared with fresh transfers.