The HCG ratio as a predictor of pregnancy outcome in assisted conception cycles

ObjectiveTo determine whether the HCG ratio can be used to predict pregnancy viability in patients undergoing IVF/ICSI treatment.Design and settingsThis was a prospective observational study conducted in a private assisted conception unit.Subjects and methodsThe patients recruited had one either a long luteal agonist protocol, a short agonist protocol, or an antagonist protocol. All patients had a maximum of three embryos transferred per cycle. Pregnancy detection was by routine serum HCG measurement on day 14 after oocyte retrieval (HCG 0) followed by another HCG sample 48h later (HCG 48). Patients with an initial positive HCG had a transvaginal ultrasound 14days later to determine viability.ResultsThree hundred and twenty patients were included in the study. We used receiver operating characteristics (ROC) analysis to predict the ability of HCG measured at 14days (HCG 0), HCG measured at 16days (HCG 48) after oocyte retrieval as well as the HCG ratio (HCG 48/HCG 0) to predict pregnancy viability as well as to predict multiple pregnancy. The HCG ratio with an optimal cut-off of 1.82 had a sensitivity of 97.6%, a specificity of 98.2% and an area under the ROC curve of 98% in the prediction of pregnancy viability. In the prediction of multiple pregnancy the HCG ratio had an optimal cut-off of 2.06 with a sensitivity of 94.5% and a specificity of only 35.6% and an area under of only the ROC curve of 64%. However, the HCG 0 with a cut-off value of 118.56mIU/ml (sensitivity 97%, specificity 96.5%) and the HCG 48 with a cut-off value of 258.16mIU/ml (sensitivity 97.2%, specificity 99.4%) were shown to be accurate in predicting a viable intrauterine multiple pregnancy with an area under the ROC curve of 97% and 99%, respectively.ConclusionThe HCG ratio with a cut-off value of 1.82 can be used to predict pregnancy viability in assisted conception cycles. Also HCG measured 14 and 16days after oocyte retrieval with a cut-off value of 118.56mIU/ml and 258mIU/ml can be used to predict viable multiple pregnancy.