Disappearance of human chorionic gonadotropin following removal of ectopic pregnancy.

A study was undertaken to determine the length of time serum beta-subunit of human chorionic gonadotropin (beta-hCG) could be detected following removal of ectopic pregnancy. Seven patients underwent complete removal of trophoblastic tissue by either salpingectomy or partial resection of the involved fallopian tube. Nine other patients had conservative surgical treatment by either linear salpingostomy or fimbrial expression of the fallopian tube. Serum beta-hCG levels were determined serially in all these patients. The results demonstrate that the initial titer of hCG is a significant factor in determining the length of time that it can be detected in the serum postoperatively. In addition, decreasing titers, conforming to the disappearance curve of hCG, as constructed in this study, are a helpful aid in avoiding further surgery in the group of patients who had a conservative removal of the trophoblastic tissue. Finally, the serum clearance of hCG by radioimmunoassay may take at least up to 24 days after surgery.