Revisiting serum beta-human chorionic gonadotropin concentrations as a predictor for dizygotic twinning after in vitro fertilization

To determine a cut-off value for beta-human chorionic gonadotropin (β-hCG) concentrations to predict dizygotic twinning after in vitro fertilization (IVF) and double embryo transfer (DET). This retrospective cohort study included 233 women who conceived after DET at IVF center, Hacettepe University Faculty of Medicine. Patients with serum P-hCG concentration 25 IU/l assayed on day 14 after oocyte retrieval were included into the study. Lower serum β-hCG concentrations were observed in non-viable pregnancy when compared to their viable counterparts. In addition, twins exhibited higher 0- hCG concentrations than singletons did. Receiver operator characteristic (ROC) curve analysis showed a significant relationship between serum βhCG concentrations and the occurrence of twin pregnancy (area under the curve = 0.85, 95% confidence interval = 0.79-0.91, p < 0.001). For twin pregnancy, when β-hCG ≥ 175 IU/l, sensitivity was 77.3%, specificity was 80.0%, positive predictive value (PPV) was 48.2%, and negative predictive value (NPV) was 93.8%. P-hCG > 175 IU/I might be used as a new cut-off value for early prediction of viable dizygotic twins following IVF-DET treatment cycles.