Prediction of ovarian hyperstimulation syndrome in women undergoing in vitro fertilization

Objective. Ovarian hyperstimulation syndrome (OHSS) is a severe side effect of in vitro fertilization (IVF). The aim of this study was to identify independent predictors which could be used to identify IVF patients at risk for OHSS. Design. A prospective observational study. Setting: University hospital. Population. Six hundred and twenty-four consecutive patients treated with conventional IVF or intracytoplasmic sperm injection. Methods. Observational clinical data were compared. Main outcome measures. Patients who developed OHSS were compared with patients who did not develop OHSS using univariate and multivariate analyses. Results. Twenty-eight patients developed OHSS considered as severe and requiring hospitalization. Independent predictors of OHSS were number of follicles at oocyte aspiration, number of aspirated oocytes and total number of medium/large-sized follicles before hCG. When these variables were combined in a receiver operating characteristic (ROC) curve they showed a sensitivity of 82.1% and a specificity of 90% for OHSS. The only independent predictor of OHSS before the ovulatory dose of hCG was total number of medium/large-sized follicles before hCG. A corresponding ROC found a sensitivity of 82.1% and specificity of 79.4%. Conclusion. Prediction of OHSS that is of severity requiring hospitalization can be done with reasonable high sensitivity and specificity both before and after the ovulatory dose of hCG.