How feasible is expectant management of interstitial ectopic pregnancy?

To review the success rate of expectant management in a series of interstitial pregnancies.

We identified all women with an ultrasound diagnosis of interstitial pregnancy seen within a 9-year period (January 2004 to April 2013). The clinical history, ultrasound findings and biochemical results were reviewed. The outcome of all interstitial pregnancies managed conservatively was recorded. Treatment was considered as successful when the serum β-human chorionic gonadotropin (β-hCG) level declined below 20 IU/L without the need for further intervention.

A total of 48 interstitial pregnancies were diagnosed during the study period. Surgery was the first-line treatment in nine (18.8%) cases. Thirty-eight (79.2%) women were offered non-surgical management: 19 (39.6%) had methotrexate (MTX) and 19 (39.6%) were managed expectantly. One (2.1%) woman returned to her local hospital following diagnosis and we were unable to obtain any follow-up information regarding her care. The median initial serum β-hCG level and ectopic size were not significantly different between any of the groups according to initial treatment. The overall success rate of expectant management was 89.5%. There were no cases of ectopic rupture in this group. Length of follow-up ranged from 7 to 141 days with a median duration of follow-up of 50.6 days.

Our data show that expectant management is an option for selected women with non-viable interstitial pregnancies and declining serum β-hCG levels, irrespective of ectopic mass size and initial serum β-hCG levels.