Endometrial thickness and volume by three-dimensional ultrasound one week after embryo transfer to detect pregnancy.

Purpose: Determine if the evaluation of endometrium one week after embryo transfer can predict pregnancy.

Methods: Endometrial volume and thickness were evaluated by three-dimensional ultrasound in 40 patients one week after embryo transfer. These results were compared to serum pregnancy test performed one week later.

Results: Twenty two patients have achieved pregnancy. A significant difference was found for endometrial volume: 6.49+/-1.97 mL vs. 3.40+/-1.11 mL (pregnant vs. not pregnant); and thickness: 11.15+/-2.75 mm vs. 9.77+/-1.85 mm. The ROC curve was used to detect the best cutoff values: endometrial volume of 3.48 mL (sensitivity-100%, specificity-68.2%) and endometrial thickness of 10.3 mm (sensitivity-72.2%, specificity-77.3%). The area under curve was significant higher for endometrial volume (0.909 vs. 0.745, P=0.027). No pregnancy was achieved in women who had an endometrial volume <3.8 mL (15 patients) or thickness < 7.9 mm (3 patients).

Conclusions: The endometrial volume and thickness were significant higher in pregnant women and this difference was more prominent for endometrial volume.