THE OVARIAN HYPERSTIMULATION SYNDROME IN IN-VITRO FERTILIZATION - A BELGIAN MULTICENTRIC STUDY .2. MULTIPLE DISCRIMINANT-ANALYSIS FOR RISK PREDICTION

The considerable overlap of distributions of values for different para meters between control and ovarian hyperstimulation syndrome (OHSS) po pulations makes any single variable inefficient for risk prediction. C ombinations of variables were studied in a discriminant function in or der to increase predictivity and decrease the false negative rate. Suc h analyses were performed on two groups of in-vitro fertilization (IVF ) patients: all OHSS cases (n = 128) (group A) and only severe OHSS ca ses (n = 92) (group B). Progressive introduction and automated stepwis e selection of variables were applied to both groups. The best predict ion (78.5%) was obtained in group A under post-oocyte retrieval condit ions using log oestradiol, slope of log oestradiol increment, human me nopausal gonadotrophin (HMG) dosage, number of oocytes retrieved and r atio of luteinizing hormone/follicle stimulating hormone (LH/FSH), in the formula. The corresponding false negative rate was 18.1%. However, effective prevention of OHSS implies the ability to withhold human ch orionic gonadotrophin injection. Therefore a formula for pre-oocyte re trieval conditions was established yielding a prediction rate of 76.1% with a false negative rate of 18.1%. To be validated, such formulae h ave to be applied to another population of IVF cases used as a 'testin g-set'.