Accuracy of Ultrasonography in Detecting Ectopic Pregnancy

To determine the accuracy of ultrasonography in detecting ectopic pregnancy. Prospective review of the outcome of women presenting with suspected ectopic pregnancy from June 2015 to December 2016, and who underwent ultrasonography in a single institution, was performed. The ultrasound findings were categorized as intrauterine pregnancy, miscarriage, ectopic pregnancy or pregnancy of unknown location. Women with pregnancy of unknown location were followed up to determine the location of the pregnancy. Those who default follow-up and persistent pregnancy of unknown location were excluded. The final outcome was confirmed either through surgical findings or follow-up obstetric ultrasound scans. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) with 95% confidence intervals (CIs) for the diagnosis of ectopic pregnancy were assessed each month. From June 2015 to December 2016, there were 2315 consecutive women who were suspected of ectopic pregnancy. Outcome data were available for 1729 (74.7%) women. The accuracy of ultrasound scan in detecting ectopic pregnancy ranges from 96.8% to 100%. There were 529 confirmed ectopic pregnancies and 1200 had either intrauterine pregnancies or miscarriages. The overall sensitivity for ultrasound in detecting ectopic pregnancy was 98.87% (95% CI: 97.55-99.58) with a specificity of 99.0% (95% CI: 98.26-99.48), a positive predictive value of 97.76% (95% CI: 96.13-98.71) and a negative predictive value of 99.5% (95% CI: 98.89-99.77). In women who are suspected of ectopic pregnancy, 98.9% of ectopic pregnancies can be accurately diagnosed by ultrasonography.