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 the 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.