Odds of ovarian hyperstimulation syndrome (OHSS) - time for reassessment

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.

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.

OHSS requiring admission to hospital occurred in 1.8% of cases. While no patients with an oestradiol level at hCG /=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.

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.