Morphometric study of the human ovary during compartmentalization

The volumetric composition of the human ovary during the compartmentalization stage has been investigated using current stereological methods. Eight left ovaries removed from three fetuses (developmental age 20-25 weeks), four neonates, and one 8-month-old child all with a 46,XX karyotype, free from malformations of the genital apparatus, were completely cut obtaining serial sections and one 1 micron-thick section every 1,000 microns was examined. Ovarian volume was 30 mm3 at the 20th week of development, 36 mm3 at the 25th week, 129 mm3 at birth, and 287 mm3 at the eighth postnatal month. The primitive cortical tissue was the largest component of the fetal ovaries (17 mm3, corresponding to 60.2% of the organ). The second component was the interstitium (21% of the organ), followed by the medulla (11.8% of the organ). The primordial follicles occupied a small part of the organs: 1.8 mm3 at 20 weeks and 3.4 mm3 at 25 weeks (respectively 6.7% and 5.4% of the volumes of the relevant ovaries). At birth, most of the organ was composed of interstitial tissue (57 mm3, 44.2% of the volume) followed by the medulla (25 mm3, 20.3% of the volume). The germinal tissue occupied 46 mm3, mainly primitive cortical tissue (14.9% of the ovary) and primordial follicles (16.3% of the ovary), with a minor contribution from the antral follicles (about 3% of the ovary).(