Serum human chorionic gonadotropin dynamics during spontaneous resolution of ectopic pregnancy.

OBJECTIVE: To study serum hCG dynamics in patients with ectopic pregnancy (EP) selected for expectant management.
DESIGN: A prospective observational study.
SETTING: Helsinki University Central Hospital, Helsinki, Finland.
SUBJECTS: One hundred eighteen patients, who were selected for expectant management among 493 patients with EP.
INTERVENTIONS: Patients were examined every 1 to 3 days using transvaginal sonography and serum hCG determinations until hCG values < 10 IU/L (conversion factor to SI unit, 1 IU/L = 2.93 pmol/L) were reached. Laparoscopy was performed if the patient developed abdominal pains or intra-abdominal hemorrhage as revealed by sonography. MAIN OUTCOME MEASURE: Serum hCG level.
RESULTS: The median gestational age at the start of follow-up in patients with a spontaneous resolution was 44 days and in patients requiring laparoscopy was 48 days. The success rate for a spontaneous resolution was 88% when the initial hCG level was < 200 IU/L but only 25% at levels > 2,000 IU/L. In the 77 patients with a spontaneous resolution, the initial median hCG concentration was 374 IU/L (range, 20 to 10,762 IU/L) and it decreased to normal in 4 to 67 days (mean, 20 days). In the 41 patients requiring laparoscopy the median initial hCG concentration was 741 IU/L (range, 165 to 14,047 IU/L); a normal level was reached in 3 to 43 days (mean, 12 days) after operation. Follow-up period before operation was 1 to 24 days (mean, 9 days). Laparoscopy was indicated in two thirds of the patients with a serum hCG level > 64% of the initial value after 7 days of follow-up.
CONCLUSIONS: Spontaneous resolution of EP correlated with a low and rapidly decreasing hCG level.