Sonographic endometrial three-layer pattern in symptomatic first-trimester pregnancy: not diagnostic of ectopic pregnancy.

PURPOSE: We evaluated a recent report that suggested that a "3-layer" appearance of the endometrium on sonography is diagnostic of ectopic pregnancy in symptomatic pregnant patients.

METHODS: We reviewed the log of pelvic sonograms performed to rule out ectopic pregnancy in women presenting with first-trimester bleeding and/or pain during a 29-month period. Medical records and sonograms of patients without sonographic evidence of intrauterine pregnancy were reviewed to determine final diagnoses and whether the 3-layer pattern was present.

RESULTS: One hundred twenty patients with available follow-up had no sonographic evidence of intrauterine pregnancy. Fifty-nine (49%) had ectopic pregnancy. An endometrial 3-layer pattern was noted sonographically in 15 patients (13%), of whom 6 (40%) had ectopic pregnancy. As a diagnostic sign of ectopic pregnancy, the endometrial 3-layer pattern had a sensitivity of 10.2%, specificity of 85.2%, positive predictive value of 40%, negative predictive value of 50.5%, and accuracy of 49.2%.

CONCLUSIONS: The endometrial 3-layer pattern is neither sensitive nor specific for the diagnosis of ectopic pregnancy.