Prediction of implantation by the sonographic appearance of the endometrium during controlled ovarian stimulation for in vitro fertilization (IVF).

The texture and the thickness of the endometrium as assessed by transvaginal sonography were prospectively evaluated in 123 patients undergoing IVF treatment. Three different types of endometrial patterns could be distinguished: (A) an entirely homogenous, hyperechogenic endometrium; (B) an intermediate type characterized by the same reflectivity of ultrasound as the myometrium, with a nonprominent or absent central echogenic line; and (C) a multilayered endometrium consisting of prominent outer and midline hyperechogenic lines and inner hypoechogenic regions. On the day before oocyte retrieval, endometrial thickness was significantly greater in the group of patients who achieved pregnancy than in the group who did not (8.7 +/- 0.4 vs 7.5 +/- 0.2 mm, respectively; P less than 0.01) and significantly more patients had multilayered, pattern C, endometrium (75% in pregnant women vs 42.4% in nonpregnant women; P less than 0.01). No pregnancy occurred when the endometrial thickness was less than 6 mm. When type C endometrium greater than or equal to 6 mm thick was seen, the pregnancy rate per embryo transfer was 39%. When type A or B endometrial pattern was seen, the negative predictive value for the occurrence of pregnancy was 90.5%. Our results suggest that transvaginal sonographic evaluation of endometrial texture and thickness may be an indicator of the likelihood of achieving pregnancy.