Establishing reference values for age-related spermatogonial quantity in prepubertal human testes: a systematic review and meta-analysis.

Objective: To collect published data on spermatogonial quantity in the testes of healthy children and calculate the reference values of spermatogonial quantities throughout prepuberty.

Design: Systematic literature search in PubMed and EMBASE focusing on the number of spermatogonia per transverse tubular cross section (S/T) and spermatogonial density per cubic centimeter (cm) of testicular volume (S/V) throughout prepuberty.

Setting: None.