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Updated: Jul 15, 2026

Whole Ovary Immunofluorescence, Clearing, and Multiphoton Microscopy for Quantitative 3D Analysis of the Developing Ovarian Reserve in Mouse
Published on: September 3, 2021
Establishment of ovarian reserve: a quantitative morphometric study of the developing human ovary
Antonino Forabosco1, Chiarella Sforza
1Medical Genetics Unit, Dipartimento Materno Infantile, Facoltà di Medicina e Chirurgia, Università degli Studi di Modena e Reggio Emilia, Modena, Italy. antonino.forabosco@unimo.it <antonino.forabosco@unimo.it>
Objective:
To assess directly the dynamics of the formation of the ovarian reserve in the normal human ovary by evaluating the total number of follicles in developing ovaries when folliculogenesis occurs.
Design:
Histomorphometry-based follicle counts in complete serial tissue sections.
Setting:
Functional Anatomy Research Center, University of Milano.
Patient(S):
Thirteen fetuses, neonates, and one 8-month-old infant.
Intervention(S):
Fifteen ovaries were completely cut, obtaining serial sections. Ovarian volume, volume fractions, density and total number of follicles per ovary were calculated using quantitative morphometric methods.
Main Outcome Measure(S):
Age-related dynamics of the establishment of ovarian reserve in human developing ovary at the end of the organogenesis.
Result(S):
The ovarian reserve (100,000 follicles at 15 weeks of postconceptional age) increased progressively to 680,000 follicles at 34 weeks. At 8 months of postnatal age the pool was still about 680,000 primordial follicles.
Conclusion(S):
The consistence of the primordial follicle pool during organogenesis shows an exponential increase until month 8 of prenatal life and it is subsequently maintained without modifications at least until month 8 of postnatal life.
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