Ultrasound evaluation of the endometrium after medical termination of pregnancy

OBJECTIVE: To determine ultrasound parameters associated with the need for clinical intervention after mifepristone and misoprostol termination of pregnancy. METHODS: Charts of patients undergoing medical termination according to a standard protocol in a 13-month period were reviewed. Endometrial thickness and the presence of gestational sac, fluid interface, or complex echoes on post-procedure ultrasonogram were recorded. Repeat doses of medication, surgical intervention, and complications were noted. Success was defined as an abortion completed after a single course of medical therapy. RESULTS: Postprocedure ultrasonograms were available for 525 of 684 patients. Endometrial thickness was measurable in 437 cases. The observed mean endometrial thickness was 4.10 ± 1.80 mm (range 0.67-13.4 mm). Endometrial thickness was inversely proportional to the number of days after initiation of therapy when ultrasonography was performed (r = -0.22; P < .001). The endometrium was thicker in the women who had failed than in those who had a successful medical abortion (6.15 ± 1.95 mm [range 3.35-10.0 mm] versus 4.01 ± 1.75 mm [range 0.67-13.4 mm], respectively; P < .001), but the wide overlap in endometrial thicknesses nullified the clinical usefulness of this difference. CONCLUSION: Endometrial thickness after administration of a single dose of mifepristone and misoprostol for medical termination should not dictate clinical intervention. The decision to treat should be based on the presence of a persistent gestational sac or compelling clinical signs and symptoms.