How is 'oogenesis' markedly different from 'spermatogenesis' with respect to the growth till puberty in the humans?

Oogenesis markedly different from Spermatogenesis because oogenesis is initiated during the embryonic developmental stage when a couple of million gamete mother cells or oogonia are formed within each fetal ovary, no more oogonia are added after birth, whereas in males the spermatogenesis begins only after attaining puberty, and the process continues even in old age.