title: Prospective evaluation of the optimal time for selecting a single embryo for transfer: day 3 versus day 5.
abstract: To determine the best day for the selection and transfer of a single embryo, a prospective, randomized study was undertaken that compared the ongoing pregnancy rate (PR) after single embryo transfer (SET) on day 3 with that after single blastocyst transfer (SBT) on day 5. Our results show an overall significantly higher PR after SBT (32.8%) compared with SET (23.2%), and a PR of 40.8% after SBT versus 25.6% after excellent-quality embryos became available.
authors.affiliation: Institute for Reproductive Medicine and Endocrinology, Bregenz, Austria. zech@ivf.at
authors.forename: Nicolas H
authors.initials: NH
authors.lastname: Zech
authors.forename: Bernard
authors.initials: B
authors.lastname: Lejeune
authors.forename: Francoise
authors.initials: F
authors.lastname: Puissant
authors.forename: Sabine
authors.initials: S
authors.lastname: Vanderzwalmen
authors.forename: Herbert
authors.initials: H
authors.lastname: Zech
authors.forename: Pierre
authors.initials: P
authors.lastname: Vanderzwalmen
mesh_terms: D000328:Adult; D004624:Embryo Transfer / Q000639:trends*; D005260:Female; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate / Q000639:trends; D011446:Prospective Studies; D013997:Time Factors