Abstract: Objective To assess the association between the depth of trophoblastic penetration into the tubal wall with serum concentrations of vascular endothelial growth factor (VEGF) and β-human chorionic gonadotropin (β-HCG). Methods Eighty patients with a diagnosis of tubal pregnancy in the ampullary region underwent radical surgical treatment (sal⁃ pingectomy), were included in this study. The serum levels of VEGF and β-HCG were detected on the day of surgery. The se⁃ rum level of VEGF was measured by ELISA. The serum level of β-HCG was quantified with a two-site immunofluorimetric assay based on the direct sandwichtechnique. Histological material was stained with Masson′s trichrome to identify muscular fibers. Immunohistochemical staining was used for human placental lactogen (hPL) to identify intermediate trophoblast and determine the depth of trophoblastic invasion into the tubal wall. The ampullary pregnancies were classified histologically according to the depth of trophoblastic infiltration into the tubal wall. Results The mean serum values of VEGF and β-HCG were significantly lower in patients with stage I tubal infiltration than those of stage Ⅱ, and which were significantly lower in patients with stage Ⅱ than those in stage Ⅲ (P＜0.05). The threshold serum value of VEGF was 308.6 ng/L, the sensitivity was 100.0% and the specificity was 92.6% for stageⅠand stage Ⅱ. The threshold serum value of VEGF was 431.9 ng/L, the sensitivity was 79.3% and specificity was 79.2% for stage Ⅱ and Ⅲ. The threshold serum value of β-hCG was 2 509.6 IU/L, the sensitivity was 91.7% and specificity was 81.5% for stageⅠ and stage Ⅱ, and levels of 13 142.6 IU/L, 72.4% and 95.8% for stage Ⅱ and stage Ⅲ. Conclusion The depth of trophoblastic penetration into the tubal wall is associated with maternal serum concentrations of VEGF and β-HCG, which can be used as the evaluation index for histological staging of trophoblas⁃ tic tissue infiltration.

Key words: vascular endothelial growth factors, chorionic gonadotropin, beta subunit, human, pregnancy, tubal, tropho? blastic cell, ROC curve