title: Relationship between pre-ICSI meiotic spindle angle, ovarian reserve, gonadotropin stimulation, and pregnancy outcomes.
abstract: OBJECTIVE
  The goals of this study are to analyze the clinical pregnancy rate as a function of the pre-intracytoplasmic sperm injection (ICSI) oocyte spindle angle and determine factors which can be associated with different spindle angles, if clinically relevant.
  
  
  METHODS
  Fifty-eight patients, who underwent their first ICSI cycle from January to December 2013, were included. Eight hundred thirty oocytes were collected, and 648 were metaphase II (MII) on retrieval day. Spindles were characterized in terms of visibility and position in relation to the first polar body (PB). Oocytes were separated into four groups based on angle: (group 1, n = 297) 0°-29°; (group 2 n = 212) 30°-89°; (group 3, n = 72) ≥90°; and those with no visible spindle (group 4, n = 67).
  
  
  RESULTS
  The rate of blastocyst development was associated with the spindle angle (p = 0.002). The rate of good quality blastocysts were as follows: group 1 (42%), group 2 (30%), group 3 (35%), and group 4 (19%) (p = 0.02). Pregnancy and live birth rates were also affected (p = 0.007 and p = 0.046, respectively). Antral follicle count (AFC) (p = 0.001), total FSH stimulating dose (p = 0.0001), and peak serum estradiol level (p = 0.0001) were associated with spindle angle grouping. Miscarriage rates trended different (p = 0.07). On the other hand, day 3 follicle-stimulating hormone (FSH) levels and female and male age were not associated with spindle angle grouping.
  
  
  CONCLUSIONS
  Embryos resulting from oocytes with pre-ICSI spindle angles between 0° and 29° were associated with better blastocyst, pregnancy, live birth, and miscarriage rates when compared to oocytes that had no visible spindle. Low ovarian reserve and excessive stimulation were also associated with lack of spindle and therefore lower pregnancy outcomes.
authors.affiliation: MUHC Reproductive Centre, 888 Demaisonneuve East suite 200, Montreal, Quebec, H2L 4S8, Canada. alina.mahfoudh@muhc.mcgill.ca.
authors.forename: Alina M
authors.initials: AM
authors.lastname: Mahfoudh
authors.affiliation: Fertility and Reproductive Health, Stanford Children Health, 1195 w Fremont Avenue, Sunnyvale, CA, 94087, USA.
authors.forename: Jeong H
authors.initials: JH
authors.lastname: Moon
authors.affiliation: MUHC Reproductive Centre, 888 Demaisonneuve East suite 200, Montreal, Quebec, H2L 4S8, Canada.
authors.forename: Sara
authors.initials: S
authors.lastname: Henderson
authors.affiliation: MUHC Reproductive Centre, 888 Demaisonneuve East suite 200, Montreal, Quebec, H2L 4S8, Canada.
authors.forename: Elena
authors.initials: E
authors.lastname: Garcia-Cerrudo
authors.affiliation: MUHC Reproductive Centre, 888 Demaisonneuve East suite 200, Montreal, Quebec, H2L 4S8, Canada.
authors.forename: Weon-Young
authors.initials: WY
authors.lastname: Son
authors.affiliation: MUHC Reproductive Centre, 888 Demaisonneuve East suite 200, Montreal, Quebec, H2L 4S8, Canada.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Dahan
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000187:drug effects / Q000648:ultrastructure; D006063:Chorionic Gonadotropin / Q000008:administration & dosage*; D004958:Estradiol / Q000097:blood; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D006801:Humans; D050498:Live Birth; D008297:Male; D009865:Oocytes / Q000254:growth & development / Q000648:ultrastructure*; D065851:Ovarian Reserve / Q000235:genetics; D010062:Ovulation Induction; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D020554:Sperm Injections, Intracytoplasmic; D008941:Spindle Apparatus / Q000648:ultrastructure*
chemical_list: D006063:Chorionic Gonadotropin; D004958:Estradiol; D005640:Follicle Stimulating Hormone
keywords: Blastocyst; Clinical pregnancy; Live birth; Polarized light microscopy (PolScope™); Spindle