Emergency department screening for ectopic pregnancy: a prospective US study

Radiology. 1994 Mar;190(3):797-802. doi: 10.1148/radiology.190.3.7509494.


Purpose: To determine the effectiveness of pelvic sonography as a screening test for ectopic pregnancy.

Materials and methods: Pelvic sonograms were prospectively analyzed in 1,427 consecutive patients with a serum level of the beta subunit of human chorionic gonadotropin of over 1,500 IU/L.

Results: Sonograms were diagnostic in 1,158 patients and indeterminate in 269. When indeterminate studies were considered falsely negative, the diagnostic accuracy was 81%. Twenty-four percent of patients with indeterminate studies were subsequently proved to have ectopic pregnancy. In ectopic pregnancy (n = 103), the most common finding was a complex adnexal mass (specificity = 92% [P < .001]). The sensitivity and specificity of screening sonography for ectopic pregnancy were 99% and 84%, respectively.

Conclusion: Pelvic sonography is an effective screening test for ectopic pregnancy. Having a one in four chance of harboring an ectopic pregnancy, patients with indeterminate studies require close follow-up. The presence of a complex adnexal mass is a strong predictor of ectopic pregnancy.

MeSH terms

  • Adult
  • Chorionic Gonadotropin / blood
  • Chorionic Gonadotropin, beta Subunit, Human
  • Emergency Service, Hospital
  • Evaluation Studies as Topic
  • False Negative Reactions
  • Female
  • Humans
  • Pelvis / diagnostic imaging
  • Peptide Fragments / blood
  • Predictive Value of Tests
  • Pregnancy
  • Pregnancy, Ectopic / diagnostic imaging*
  • Pregnancy, Ectopic / epidemiology
  • Prospective Studies
  • Sensitivity and Specificity
  • Ultrasonography / methods
  • Ultrasonography, Prenatal*


  • Chorionic Gonadotropin
  • Chorionic Gonadotropin, beta Subunit, Human
  • Peptide Fragments