Risk factors for persistent trophoblastic activity after surgery for ectopic pregnancy.

BACKGROUND

The purpose of this study was to explore the value of preoperative ultrasound and human chorionic gonadotropin (hCG) monitoring to predict the occurrence of residual trophoblastic tissue after laparoscopic conservative surgery for tubal pregnancy.

METHODS

During the period from January 1998 to December 1999 all 206 women undergoing treatment for ectopic pregnancy at the Karolinska hospital were included in the study. A vaginal ultrasound examination was performed and the ectopic size was measured. Serum-hCG levels were recorded preoperatively, and at days 1-2 and 14-21 after surgery.

RESULTS

A diameter of 8 mm or less was observed in 13 of the 14 patients needing secondary treatment. The risk of second surgery if the finding at the preoperative ultrasound was larger than 8 mm was 1/73 resulting in a negative predictive value of 0.01. A considerable overlap in the hCG levels was found on days 1-2 after surgery between women with and without second surgery.

CONCLUSIONS

Using a single cutoff point for hCG seems to be of little value as residual trophoblastic tissue can manifest itself at different times--early or late--during the postoperative period. Women with a small ectopic pregnancy as detected by preoperative vaginal ultrasound are at high risk of developing residual trophoblastic tissue. These patients should be considered by the surgeon and monitored with hCG levels until values decline and become undetectable. Management of patients with slowly but declining values can be conservative. If hCG levels are rising or do not decline, methotrexate (MTX) can be an alternative.