THE RELATION BETWEEN DEPTH OF TROPHOBLASTIC INVASION AND BETA-HCG LEVELS IN TUBAL PREGNANCIES

beta-HCG (human chorionic gonadotropin) values of over 2500 I.U./1 are associated with higher failure rates for therapy with prostaglandin F 2 alpha in tubal pregnancies. The purpose of our study was to ascertai n if the 2500 I.U./1 limit correlates with histopathology. We therefor e compared the pre-operative beta-HCG-values and intraluminal and extr aluminal trophoblast growth in tubal pregnancy. Purely intraluminal tr ophoblast was significantly more frequent in patients of group I (beta -HCG < 2500 I.U./1), while group II patients (P-HCG > 2500 I.U./1) alm ost exclusively had extraluminal growth (P=0.0045). Since the efficacy of prostaglandin F2 alpha therapy depends on intact tubal musculature the correlation of the beta-HCG threshold level with histopathologic findings may explain the high failure rate in patients with beta-HCG v alues above 2500 I.U./1.