摘要：Objective: Optimizing the cut-off level for a single serum hCG determination around day 15 after oocyte retrieval or ovulation. Study design: Retrospective data analysis. Results: 204 hCG samples >5 IU/L between march and October 1999 taken on day 14, 15 or 16 after oocyte retrieval in 204 patients undergoing IVF or ICSI were analyzed. ROC-curves and optimal cut-off levels to discriminate between viable and non-viable pregnancies were calculated for each day separately. Cut-off levels were found at 76, 142 and 223 IU/L for day 14, 15 and 16, respectively, and were verified by 487 hCG samples >5 IU/L taken between january 2000 and june 2004. Conclusions: A single serum hCG determination on day 14 or 15 is sufficient to discriminate viable pregnancies accurately from non-viable pregnancies.