The role of sonographic endometrial patterns and endometrial thickness in the differential diagnosis of ectopic pregnancy

Objective: The purpose of this study was to examine the usefulness of the endometrial trilaminar pattern and thickness in the diagnosis of ectopic pregnancy. Study design: We reviewed patient records for clinical and ultrasonographic data for patients with the suspicion of ectopic pregnancy. The trilaminar pattern and endometrial thickness were tested as predictors for the diagnosis of ectopic pregnancy. Results: The trilaminar pattern had a specificity of 94% and sensitivity of 38% (n= 403 women). The mean endometrial thickness was thinner in patients with ectopic, compared with normal pregnancy (9.5 ± 5.7 mm vs 12.4 ± 5.9 mm; P =.035). Patients with normal pregnancy or first-trimester losses had comparable thicknesses (12.4 ± 5.9 mm vs 12.5 ± 8.0 mm). The receiver operator curve showed that there was no thickness value useful for the diagnosis of ectopic pregnancy. Conclusion: The trilaminar pattern is specific for the diagnosis of ectopic pregnancy, but it is associated with low sensitivity. The endometrial thickness tends to be thinner in patients with an ectopic pregnancy.