Ultrasonographic appearance of the endometrium in natural and stimulated in-vitro fertilization cycles and its correlation with outcome

Ultrasonographic evaluation of the endometnum in 56 IVF patients was performed prospectively. Endometrial thickness and pattern were analysed in 18 natural-cycle and 38 stimulated-cycle patients. Thickness was measured from the echogenic interface of the endometrium-myometrium junc tion on a transverse section at the level of the fundus. Patterns were classified as A (homogeneous, hyperechogenic), B (mixed, with an outer hyperechogenic and inner hypoechogenic layer) or C (fluid-filled cavum with ring configuration). The thickness and pattern distributions were similar in natural- and stimulated-cycle patients. There was no cor-relation between thickness and serum oestradiol levels, the diameter of the largest follicle or the pregnancy outcome in either group. However, the occurrence of endometrial pattern A on the day prior to oocyte retrieval had a predictive value of 100% for a non-conceptional cycle. In contrast, pattern B occurred in a significantly greater proportion of pregnant than non-pregnant patients.