CLEARANCE CURVES OF SERUM HUMAN CHORIONIC-GONADOTROPIN FOR THE DIAGNOSIS OF PERSISTENT TROPHOBLAST

A well recognized hazard of conservative surgical treatment of tubal p regnancy is incomplete removal of trophoblastic tissue, Persistent tro phoblast can be detected by postoperative serum human chorionic gonado trophin (HCG) monitoring, The impact of various surgical techniques on the post-operative clearance of serum HCG was investigated in a retro spective study, The medical records of 97 patients treated surgically for tubal pregnancy in the Academic Medical Center of the University o f Amsterdam, The Netherlands, between 1 January 1992 and 1 August 1994 were reviewed; 28 patients were treated by salpingostomy by laparosco py, 16 by salpingostomy by open surgery and 53 by salpingectomy by eit her method, There was no difference in the post-operative clearance of serum HCG after successful conservative surgery compared to radical s urgery, However, persistent trophoblast occurred in eight patients (29 %) after laparoscopic salpingostomy and in only one patient (6.3%) who had a salpingostomy by open surgery (relative risk 4.57), Serum HCG c learance curves allow early identification of patients with persistent trophoblast after conservative surgical treatment. Moreover, monitori ng of post-operative serum HCG until it becomes undetectable is mandat ory in order to reveal late-onset types of persistent trophoblast.