The Reliability of Transvaginal Ultrasonography for the Diagnosis of Incomplete Abortion after Spontaneous First-trimester Abortion

Abstract

The Reliability of Transvaginal Ultrasonography for the Diagnosis of Incomplete Abortion after Spontaneous First-trimester Abortion

Pragaypruek      Tungtong            MD

Department of Obstetrics and Gynecology, Taksin Hospital

Objective: To assess the reliability of transvaginal ultrasonography for the diagnosis of incomplete abortion after spontaneous first-trimester abortion.

Study design: Diagnostic study.

Subjects: Sixty four patients with spontaneous first-trimester abortion at Taksin hospital during August 2005 to May 2006 were enrolled.

Methods: All patients underwent transvaginal ultrasonography. When ultrasonographic finding showed incomplete abortion, uterine curettage was the next management. If the result revealed complete abortion, urine pregnancy test was examined to confirm the diagnosis.

Main outcome measures: Pathological report, urine pregnancy test, endometrial thickness, sensitivity, specificity, positive predictive value and negative predictive value.

Results: Depend on the diagnostic criteria of transvaginal ultrasonographic from previous studies, the sensitivity, specificity, positive predictive value and negative predictive value were 100%, 23.5% (95%CI:  13.1-33.9),  53.6% (95%CI:  41.3-65.8) and 100%. By using endometrial thickness, mean endometrial thickness in complete and incomplete abortion were 9.44.3 mm and 16.25.5 mm. The thickness between two groups was statistically different (p-value  0.001). The ROC curve for endometrial thickness showed that the best cut-off value was 12.2 mm. The sensitivity, specificity, positive predictive value and negative predictive value of this thickness were 80% (95%CI:  70.2-89.8), 73.5% (95%CI:  61.7-84.3), 72.7% (95%CI:  61.8-83.6) and 80.7% (95%CI:  70.9-90.3).

Conclusion: The reliability of transvaginal ultrasonography for the diagnosis of incomplete abortion after spontaneous first-trimester abortion depends on the diagnostic criteria. Endometrial thickness at 12.2 mm. was a good criterion with high sensitivity and specificity.

Key word: transvaginal ultrasonography, incomplete abortion, endometrial thickness

Vajira Med J 2006 ; 50 : 73 - 80