In an attempt to determine whether the secular trend toward an earlier onset of puberty has continued over recent decades in the United States of America, published reports concerning the age of attainment of pubertal events have been reviewed. Such reports are very limited and vary in both design and inclusive ages of study subjects. Among females, two recent large cross-sectional studies indicate that fifty percent of females in the United States attain Tanner breast stage 2 at 9.5 to 9.7 years of age. This is younger than previously thought, although adequate earlier studies of girls in the United States are not available for comparison. These two studies also indicate that about 14% of girls attain Tanner stage 2 while 8 years of age; one study extends earlier reporting that about 6% exhibit onset of breast development while 7 years of age. There is no evidence that the age of menarche or the attainment of adult (Tanner 5) breast development has decreased over the past 30 years. The data also suggest an earlier onset of Tanner stage 2 pubic hair but no change in attainment of stage 5. Among males, pubic hair may be appearing at younger ages, but data are inadequate or too inconsistent to allow firm interpretation. The lack of standardization of genital criteria of pubertal onset in the male makes any conclusions regarding secular trends impossible. In summary, earlier secular trends over recent decades related to better health, improved nutrition or socio-economic status, or any putative influence by endocrine disrupters cannot be verified.

In men with a history of unilateral cryptorchidism small testicular size at orchiopexy is not associated with decreased paternity (89.8%), abnormal hormone levels, a lower sperm count or decreased testicular volume in adulthood.

FSH levels are significantly higher and sperm counts are significantly lower in formerly cryptorchid men than in controls. In the cryptorchidism group the same differences are found in fertile and infertile men. Thus, elevated FSH and low sperm counts may be considered risks for infertility in formerly cryptorchid men.

This study suggests that men who underwent orchiopexy in later childhood have subclinically decreased Leydig cell function. It may result in a less than optimal hormonal milieu for adult reproductive function. These data provide support for orchiopexy during infancy to preserve Leydig cell function and, thereby, potentially enhance fertility.

This study failed to indicate that paternity is diminished among men with a single testis compared with the general population, regardless of the origin of the loss. About 12% of unilateral impalpable testes judged to be impalpable on examination before surgery were found to be absent after surgical exploration.