Age-Related Structural and Metabolic Changes in the Pelvic Reproductive End Organs

In this work, we provide preliminary data and a review of the literature regarding normal structural and functional changes that occur in the aging uterus, ovary, testicle, and prostate gland. It is expected that such knowledge will help physicians to distinguish physiologic changes from pathologic changes at an early stage. We retrospectively reviewed pelvic magnetic resonance imaging (MRI) scans of 131 female and 79 male subjects ages 13 to 86 years to determine changes in volume of the uterus, ovary, and prostate gland with age. Scrotal ultrasound examinations of 150 male subjects ages 0 to 96 years also were analyzed retrospectively to determine changes in testicular volume with age. In addition, 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) scans of 145 male subjects ages 11 to 90 years were analyzed retrospectively to assess for changes in maximum standardized uptake value (SUVmax) of the testicles with age. The uterus had a mean volume of 38.55 ± 3.68 cm3 at 17 to 19 years of age, increased to a peak volume of 71.76 ± 19.81 cm3 between 35 to 40 years, and then declined to 24.02 ± 8.11 cm3 by the eighth decade of life. The maximal ovarian volume per subject maintained a relatively stable size in early life, measuring 9.46 ± 3.25 cm3 during the second decade of life, 8.46 ± 3.32 cm3 in the mid-fourth decade of life, and 7.46 ± 3.33 cm3 at 45 years of age, after which it declined to 4.44 ± 2.02 cm3 by the late fifth decade of life. The ovaries were not identifiable on MRI in subjects beyond the sixth decade of life. The volume of the prostate increased from 23.45 ± 6.20 cm3 during the second decade of life to 47.5 ± 41.59 cm3 by the late eighth decade of life; the central gland of the prostate increased from 9.96 ± 3.99 cm3 to 29.49 ± 28.88 cm3 during the same age range. Mean testicular volume was 11.2 ± 5.9 cm3. Testicular volume increased with age from birth to 25 years. After age 25, there was a significant decline in the testicular volume. The mean SUVmax for the testicles was 1.9 ± 0.5. Testicular metabolic activity demonstrated an increasing trend until the age of 35 years. A plateau in SUVmax was observed after the age of 35 years until the age of 65 years. A slight decrease in SUVmax was observed after the age of 65 years. The pelvic structures of men and women change both structurally and functionally over the lifespan, and such changes can be quantified using ultrasound, MRI, and 18F-FDG-PET.