Approximately how many primordial follicles are present in neonates?

• A. 400,000
• B. 40,000
• C. 4,000
• D. 400

Answer: (A)

Primordial follicles are the finite ovarian reserve established during fetal life and kept in a resting state until puberty. The main idea here is the size of that reserve at birth. In humans, the newborn ovary contains a very large pool of these follicles—roughly one to two million. This substantial starting number reflects the long reproductive lifespan available later on. As life progresses, many follicles undergo atresia, and only a small portion are recruited each cycle for ovulation. By puberty the pool has diminished to about a few hundred thousand (roughly 300,000–400,000 in many individuals), and by menopause only a few hundred or a few thousand remain. So, the neonatal count is on the order of one to two million primordial follicles.