[HCG in serum and peritoneal fluid in suspected ectopic pregnancy]

HCG was measured in peripheral serum and peritoneal fluid (PF), obtained by punction of the Douglas pouch (n = 12) or by laparoscopy (n = 14) in 26 patients with suspected ectopic pregnancy. In 10 patients with tubal pregnancy, the hCG-concentration in the PF was in every case higher than in serum. Contrary to this, in 11 disturbed and 2 normal intrauterine pregnancies the PF-hCG was lower than in serum. No hCG-gradient could be observed in 1 patient with an interstitial pregnancy. Moreover, in 2 patients with inconclusive laparoscopic findings, the PF-hCG was higher than in serum; this pointed to a probable harbouring of a suspected missed ectopic pregnancy, and treatment was therefore conservative. The PF-hCG level 35 h after i. m. application of 5000 IU hCG to non-pregnant women varied between 11 and 42% as compared to that of the serum. It is concluded that the gradient of hCG between PF and serum can be used for the verification of a suspected ectopic pregnancy in addition to other diagnostic methods.