Paired human chorionic gonadotrophin determinations for the prediction of pregnancy outcome in assisted reproduction

The aim of this study was to determine the prognostic value of single andpaired measurements of serum concentrations of human chorionicgonadotrophin (HCG) for successful pregnancy following in-vitrofertilization (IVF) and tubal embryo transfer (TET). We analysed serum HCGconcentrations 15 and 22 days after IVF or TET in 198 conception cycles.Cut-off values of serum HCG were determined by a receiver operatingcharacteristic (ROC) curve. On the basis of single HCG samples on day 15(HCG15) after transfer, using a cut-off value of HCG15 = 150 mIU/ml, thesensitivity was 71% and the specificity was 77%. The positive predictivevalue (HCG15 > or = 150 mIU/ml indicating a normal pregnancy) was 89%,while the negative predictive rate (HCG15 < 150 mIU/ml indicating anabnormal pregnancy) was 51%. Patients with HCG15 < 150 mIU/ml butHCG22/HCG15 ratio > or = 15, still had a 90% chance of normal pregnancy.However, in patients with HCG15 < 150 mIU/ml and an HCG22/HCG15 ratio< 15, there was an 84% chance of an abnormal pregnancy. We conclude thata single HCG15 determination combined with the ratio of HCG22 to HCG15 hasa higher diagnostic accuracy for prediction of pregnancy outcome thaneither analysis alone.