[The corpus luteum in the ultrasound image and its endocrine function]

The corpora lutea of 38 patients with sterility problems were sonographically measured. In a total of 51 cycles the corpus luteum values were compared with the estradiol (E2) and progesterone (P) plasma levels on the day of sonographic examination (SE). In 49 SEs performed immediately following ovulation the corpus luteum was cystic in 26 cases (means = 14.9 mm) and solid in 23 cases (means = 12.8 mm, p less than 0.05). The postovulatory differences between the corresponding E2 and P values, respectively, were not significant. In the midluteal phase the corpora lutea were cystic in 22 cases (means = 18.2 mm) and solid in 14 (means = 13.4 mm, p less than 0.001). Both E2 (means = 362.8 pg/ml) as well as P (means = 27.7 ng/ml) were higher in the women with cystic than in those with solid corpora lutea (E2 means = 222 pg/ml; P means = 19.4 ng/ml; p less than 0.01 in each case). When the patient collective was split into two groups, with and without stimulation therapy, a significantly higher E2 was only found in the "with therapy" group in patients with cystic corpus luteum in the midluteal phase. The size of the midluteal corpus luteum correlated in particular with the E2 plasma concentrations in all patients (p less than 0.005). Thus, in addition to sonographic measurement of the endometrium, sonographic demonstration of the corpus luteum is also useful in assessing the luteal phase.