Ectopic pregnancy: prospective study with improved diagnostic accuracy.

STUDY OBJECTIVE: To assess the utility of ultrasonography, quantitative serum beta-human chorionic gonadotropin (beta-hCG) level, history, and physical examination in the diagnosis of ectopic pregnancy (EP) in the emergency department.

METHODS: We prospectively studied 481 consecutive pregnant patients who presented to an urban ED with first-trimester abdominal pain or vaginal bleeding. History, physical examination findings, quantitative beta-hCG values, sonography findings, surgical findings, and final diagnosis were collected after patient enrollment in the study. We assessed the proportions of pregnant patients experiencing pain or bleeding with EPs versus those with abnormal and normal intrauterine pregnancies (IUPs).

RESULTS: Pregnant women with abdominal pain or vaginal bleeding received beta-hCG values; positive radioimmunoassays prompted ultrasonography; indeterminate ultrasonography findings resulted in admission. Thirteen percent of patients had confirmed EPs; 99.5% of patients discharged from the ED had documented IUPs. Transvaginal sonography in the ED established EP or IUP in 75%. For EP detection, sonography is 69% sensitive and 99% specific. Single beta-hCG levels are useful in predicting EP; a beta-hCG value of 1,000 mIU/mL or lower shows a fourfold higher risk of EP. History and physical examination do not reliably diagnose or rule out EP; of EP patients, 9% reported no pain and 36% lacked adnexal tenderness.

CONCLUSION: To prevent delayed diagnosis of EP in urban centers, pregnant women with abdominal pain or vaginal bleeding require evaluation by transvaginal ultrasonography. Indeterminate ultrasonography findings necessitate further evaluation. A beta-hCG level of 1,000 mIU/mL or lower should heighten suspicion of EP.