title: Odds of ovarian hyperstimulation syndrome (OHSS) - time for reassessment.
abstract: BACKGROUND
  Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening complication of Assisted Reproductive Technology (ART) treatment. The objective of this study was to assess the odds of OHSS hospital admission in relation to oestradiol levels on day of hCG administration and number of oocytes collected.
  
  
  METHODS
  We performed a 24 months retrospective analysis of a cohort of patients receiving ART treatment in a University teaching hospital including all patients requiring admission due to OHSS. Main outcome measures were oestradiol levels, number of oocytes collected and incidence of admission with OHSS.
  
  
  RESULTS
  OHSS requiring admission to hospital occurred in 1.8% of cases. While no patients with an oestradiol level at hCG </=15,000 pmol/L developed OHSS, those with oestradiol levels >/=15,000 pmol/L had different risks of admission according to the number of oocytes collected: those with >30 oocytes were 6.7 times more likely to be admitted that those with <20 oocytes.
  
  
  CONCLUSIONS
  This study identifies an oestradiol level (>/=15,000 pmol/L) and number of oocytes (>/=20) above which the odds of being admitted with OHSS increases significantly. Although OHSS cannot always be prevented, these measurable parameters should be used to allow appropriate counselling and subsequent safe management of ART patients.
authors.affiliation: Human Assisted Reproduction Ireland (HARI) Unit, Dublin, Ireland. emocanu@rcsi.ie
authors.forename: Edgar
authors.initials: E
authors.lastname: Mocanu
authors.forename: Marie Louise
authors.initials: ML
authors.lastname: Redmond
authors.forename: Bernadette
authors.initials: B
authors.lastname: Hennelly
authors.forename: Claire
authors.initials: C
authors.lastname: Collins
authors.forename: Robert
authors.initials: R
authors.lastname: Harrison
mesh_terms: D002452:Cell Count; D006063:Chorionic Gonadotropin / Q000008:administration & dosage; D004624:Embryo Transfer; D004958:Estradiol / Q000097:blood; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D009865:Oocytes / Q000166:cytology; D016471:Ovarian Hyperstimulation Syndrome / Q000097:blood / Q000453:epidemiology*; D010062:Ovulation Induction / Q000009:adverse effects; D011247:Pregnancy; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects; D012189:Retrospective Studies; D012307:Risk Factors