title: Characterization of the injection funnel during intracytoplasmic sperm injection reflects cytoplasmic maturity of the oocyte.
abstract: OBJECTIVE
  To quantify cytoplasmic maturity on the basis of intracytoplasmic sperm injection (ICSI) injection funnel manifestation and to evaluate influence factors of the latter.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Private fertility center.
  
  
  METHODS
  A total of 31 patients with good ovarian response.
  
  
  METHODS
  Mature and immature oocytes were injected intracytoplasmatically. Formation and persistence of an injection funnel was documented and measured.
  
  
  METHODS
  ICSI funnel size, persistence of injection funnel, rates of degeneration and fertilization, embryo quality.
  
  
  RESULTS
  Funnel volume in germinal vesicle stage oocytes (prophase I [PI]) was significantly smaller than that of metaphase I (MI) and MII oocytes. Immature eggs (PI, MI) almost never showed a persistent funnel 2-4 minutes after ICSI, whereas in MII eggs the funnel was still observable in 35% (117/334) of the cases. Uni- and multivariate analysis revealed that pipette type and stimulation protocol significantly influenced appearance of injection funnel. Funnel volume in oocytes that fertilized regularly was significantly higher compared with three-polar body and degenerated oocytes.
  
  
  CONCLUSIONS
  Oocyte maturation within the follicle is closely associated with a remarkable change in cytoplasm viscosity from an aqueous to a more viscous subtype. Precise evaluation of the injection funnel may help to explain deviations from expected ICSI outcome and could also assist in optimizing controlled ovarian hyperstimulation.
authors.affiliation: Zentrum für IVF und Reproduktionsmedizin, Amedes Deutsche Klinik, Bad Münder, Hannover, Germany.
authors.forename: Iris
authors.initials: I
authors.lastname: Krause
authors.affiliation: Zentrum für IVF und Reproduktionsmedizin, Amedes Deutsche Klinik, Bad Münder, Hannover, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Pohler
authors.affiliation: Zentrum für IVF und Reproduktionsmedizin, Amedes Deutsche Klinik, Bad Münder, Hannover, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Grosse
authors.affiliation: Department of Gynecology, Obstetrics, and Gynecologic Endocrinology, Kepler University Hospital, Linz, Austria.
authors.forename: Omar
authors.initials: O
authors.lastname: Shebl
authors.affiliation: Institute of Human Genetics, Medical University of Graz, Graz, Austria.
authors.forename: Erwin
authors.initials: E
authors.lastname: Petek
authors.affiliation: Zentrum für IVF und Reproduktionsmedizin, Amedes Deutsche Klinik, Bad Münder, Hannover, Germany.
authors.forename: Arvind
authors.initials: A
authors.lastname: Chandra
authors.affiliation: Department of Gynecology, Obstetrics, and Gynecologic Endocrinology, Kepler University Hospital, Linz, Austria. Electronic address: thomas.ebner@gespag.at.
authors.forename: Thomas
authors.initials: T
authors.lastname: Ebner
mesh_terms: D000328:Adult; D003593:Cytoplasm; D005260:Female; D006801:Humans; D007246:Infertility / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D049469:Meiotic Prophase I; D008677:Metaphase; D008853:Microscopy; D009865:Oocytes; D011247:Pregnancy; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic; D013997:Time Factors; D016896:Treatment Outcome; D014783:Viscosity
keywords: ICSI; ICSI pipette; Injection funnel; controlled ovarian hyperstimulation; cytoplasmic maturity