Trends in ovarian hyperstimulation syndrome hospitalization rates in the USA: an ongoing concern.

Ovarian hyperstimulation syndrome (OHSS) is a serious, almost exclusively, iatrogenic complication of ovarian stimulation. Many techniques have been developed over the past 25 years to decrease OHSS risks, and most have been in common use for 15-20 years. In view of these techniques, it could be hypothesized that severe OHSS rates would decrease or almost disappear. According to the US National ART Surveillance System, rates did not change significantly between 2000 and 2009, at 106 OHSS cases per 10,000 IVF cycles annually. In the present study, OHSS-related hospital admissions were evaluated to establish whether a decline has occurred in OHSS admissions since the development of preventative strategies. A retrospective-population-based study was conducted using data from the Health-Care Cost and Utilization Project-Nationwide-Inpatient-Sample database between 2004 and 2014 inclusively. Between 2004 and 2008, admissions of OHSS decreased in absolute numbers and rates; however, these statistics plateaued, remaining stable between 2008 and 2014. Despite this, OHSS remains a concern and is clearly not a disease of the past. The financial burden of OHSS hospitalizations likely persists. Although techniques have resulted in a decrease in OHSS admissions since 2004, this change has plateaued, and therefore efforts to further reduce OHSS must continue.