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Age-related features of the male genitalia
Last reviewed: 06.07.2025
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The testicle grows slowly before puberty (13-15 years), and then its development accelerates sharply. By the age of 14, the length of the testicle increases by 2-2.5 times (up to 20-25 mm), and the weight reaches 2 g. At 18-20 years, the length of the testicle is 38-40 mm, and the weight increases to 20 g. In adulthood (22 years and later), the size and weight of the testicle increase slightly, and after 60 years they decrease slightly. At all ages, the right testicle is larger and heavier than the left and is located above it.
The epididymis is relatively large. The length of the epididymis in a newborn is 20 mm, the weight is 0.12 g. During the first 10 years, the epididymis grows slowly, then its growth accelerates.
The appendix of the testicle, appendage of the appendix of the testicle and appendage of the appendix of the epididymis in a newborn are relatively large in size, grow until 8-10 years, and then gradually undergo reverse development.
In a newborn, the convoluted and straight seminiferous tubules, as well as the tubules of the rete testis, do not have a lumen, which appears by the period of puberty. In adolescence, the diameter of the seminiferous tubules doubles, in adult men it increases 3 times compared to the diameter of the seminiferous tubules in newborns.
By the time of birth, the testicles should have descended into the scrotum. However, if the descent of the testicles in a newborn is delayed, they may be located in the inguinal canal (retroperitoneal). In these cases, the testicles descend into the scrotum later, with the right testicle located higher than the left.
The diameter of the spermatic cord in a newborn is 4.0-4.5 mm. The vas deferens is very thin, the longitudinal muscle layer in its wall is absent (it appears by the age of 5). The muscle that lifts the testicle is poorly developed. Until the age of 14, the spermatic cord and its constituent structures grow slowly, and then their growth accelerates. The thickness of the spermatic cord in a 15-year-old teenager is approximately 6 mm, the diameter of the vas deferens is 1.6 mm.
The seminal vesicles in a newborn are poorly developed, the length of the vesicle is 1 mm, the cavity is very small. Up to 12-14 years, the seminal vesicles grow slowly, in adolescence (13-15 years) their growth accelerates, the size and cavity increase noticeably. With age, the position of the seminal vesicles changes. In a newborn, they are located high due to the high position of the urinary bladder, covered on all sides by the peritoneum. By 2 years, the vesicles descend and end up lying retroperitoneally. The peritoneum is adjacent only to their tops. The ejaculatory ducts in a newborn are short (8-12 mm long).
In newborns and infants (up to 1 year), the prostate gland is spherical, since the right and left lobes are not yet expressed. The gland is located high, soft to the touch, the glandular tissue is not developed. Accelerated growth of the gland is observed after 10 years. By adolescence, lobes appear and the gland acquires a shape characteristic of the gland of an adult. During this period, the internal opening of the male urethra seems to shift to the anterior-superior edge of the prostate gland. The glandular parenchyma of the prostate gland develops rapidly in adolescence. At this time, the prostatic ducts are formed and the gland acquires a shape characteristic of the gland of an adult man. By the age of 20-25, the prostate gland is fully developed. In 30-50% of men over 55-60 years of age, an increase in the prostate gland is observed, mainly its isthmus (prostatic hypertrophy). The mass of the gland in a newborn is 0.82 g, at 1-3 years - 1.5 g, during the second childhood (8-12 years) - 1.9 g, and in adolescence (13-16 years) - 8.8 g.
The bulbourethral glands in a newborn are poorly developed, their epithelium and capsule are poorly differentiated.
The length of the penis in a newborn is 2.0-2.5 cm, the foreskin is long, completely covering the head of the penis. The penis grows slowly until puberty, and then its growth accelerates.
The scrotum of a newborn is small in size, its skin is wrinkled due to the presence of a well-developed fleshy membrane. Intensive growth of the scrotum is observed during puberty.
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