Time Lags Between Various Maturity Measures and Spermarche

In a longitudinal study of 40 normal boys aged 8-11, followed biannually for up to 7 years, researchers investigated the timing of various maturity measures relative to spermarche, which is the onset of sperm release. Spermarche was estimated by detecting spermatozoa in quarterly collected 24-hour urine samples. The study found that certain maturity measures occurred before spermarche: testis size greater than 4 ml occurred 16 months prior, pubic hair stage greater than Tanner stage one occurred 10.5 months prior, and the first occurrence of a broken voice happened just 0.5 months before spermarche. Following spermarche, the age of maximal height growth velocity was reached after 5.5 months, axillary hair stage greater than one after 8 months, beard growth after 12 months, and the occurrence of acne after 13 months. The confidence limits for these time lags were approximately ± 4 months.