title: Oocyte and embryo quality after coasting: the experience from oocyte donation.
abstract: BACKGROUND
  Oocyte donation provides us with an opportunity to study the clinical outcome of oocytes, retrieved from women undergoing coasting, in recipients in whom endometrial receptivity is unaltered by the coasting procedure. Thus, our aim was to describe oocyte donation outcome in donors undergoing coasting, the oocyte and embryo quality obtained from these cycles, and to determine the influence of coasting duration in the cycle outcome.
  
  
  METHODS
  Matched-paired analysis included 15 oocyte donors with high response to ovarian stimulation and submitted to coasting and 15 oocyte donors with normal response to ovarian stimulation and not undergoing coasting. There were 38 oocyte recipients who shared oocytes from the donors under coasting and 37 from donors not undergoing coasting.
  
  
  RESULTS
  Both groups of donors were comparable in terms of days and dose of ovarian stimulation, oocytes retrieved, metaphase II oocytes obtained, and in the appearance of ovarian hyperstimulation syndrome. Both groups of oocyte recipients were comparable in male-associated factor, pregnancy and implantation rates, as well as in embryo quality. Recipients from donors with coasting for >4 days had significantly lower implantation and pregnancy rates.
  
  
  CONCLUSIONS
  the outcome of oocyte donation from donors undergoing coasting is not impaired, as good implantation and pregnancy rates are achieved. Embryo quality, according to our current standards, does not seem to be compromised by coasting itself. However, if coasting in oocyte donors is prolonged for >4 days there is a significant decrease in both implantation and pregnancy rates.
authors.affiliation: Instituto Valenciano de Infertilidad-Madrid, C/Santiago de Compostela 88, 28035 Madrid, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Isaza
authors.forename: J A
authors.initials: JA
authors.lastname: García-Velasco
authors.forename: M
authors.initials: M
authors.lastname: Aragonés
authors.forename: J
authors.initials: J
authors.lastname: Remohí
authors.forename: C
authors.initials: C
authors.lastname: Simón
authors.forename: A
authors.initials: A
authors.lastname: Pellicer
mesh_terms: D000328:Adult; D004334:Drug Administration Schedule; D010064:Embryo Implantation; D004622:Embryo, Mammalian / Q000502:physiology*; D005260:Female; D006062:Gonadotropins / Q000008:administration & dosage* / Q000627:therapeutic use; D006801:Humans; D018587:Oocyte Donation; D009865:Oocytes / Q000502:physiology*; D016471:Ovarian Hyperstimulation Syndrome / Q000517:prevention & control; D011247:Pregnancy; D018873:Pregnancy Rate; D013997:Time Factors
chemical_list: D006062:Gonadotropins