General Medical Information

Ovarian Size

Andrew S. Cook

Ovarian size has been evaluated sonographically in premenarcheal, menstruating, and postmenopausal women. These studies agree that the normal ovarian size is different in each group; however, the actual value is subject to controversy. The ovarian volume of menstruating omen has been most widely studied and is the standard against which the premenarcheal and postmenopausal ovarian size is compared. Classically, the ovary of a menstruating woman was described as measuring 1 × 2 × 3 cm. Using the mathematical formula to estimate the volume of a prolate ellipse (height × width × length × 0.523), this represents an ovarian volume, in menstruating women, of 3 cm3. An ovarian volume, in menstruating women, of 6 cm3 also has been quoted as normal. This corresponds to dimensions of 2 × 2 × 3 cm3. A range in ovarian volume from 4.4 to 9.8 cm3 has been documented by sonographic evaluation.

Sonographic estimates of premenarcheal ovarian size have varied. Difficulty in sonographic visualization of the ovaries in young girls was experienced initially. Recent reports have visualized the majority of premenarcheal ovaries, including those in infants. Ivarson demonstrated an average ovarian volume of 0.7 cm3 by sonographic evaluation. The authors also used the histologic data of Simkins to calculate the ovarian volume using the prolate ellipsoid formula. Patients 6 months to 2 years had an average ovarian volume of 0.41 cm3, and patients 7 to 9 years had an average ovarian volume of 0.74 cm3. Stanhope sonographically evaluated 40 premenarcheal girls age 6 months to 14 years. At 2 years of age, the average volume was 1 cm3 and at 12 years the volume was 2 cm3.

Cohen studied ovarian volume of 725 consecutive patients (1,157 ovaries) by ultrasound. The average volume of menstruating women in this study was 9.8 cm3, which is on the upper end of normal values reported in the literature. The age of range of premenarcheal patients was 3 to 15 years (average 9.5 years). The average volume of 32 premenarcheal ovaries was 3.0 cm3. The mean volume of patients in the first decade of life (19 ovaries) was 1.7 cm3. Salardi sonographically measured the ovaries of 101 premenarcheal girls. The mean ovarian volume was determined for each year, from age 2 to 13 years. Ovarian size is stable until about 5 years, when age-related growth begins.