Exemestane increases the number and improves the morphology of cultured pre-antral follicles from transmasculine ovarian cortical tissue.

To enhance fertility preservation options, it would be beneficial to develop culture platforms starting from cryopreserved-thawed ovarian cortical tissue. Importantly, ovarian cortical tissue from cisgender females (cOVA) and transmasculine individuals (tOVA) respond differently to culture and may require specific conditions to support optimal folliculogenesis. We explored the role of CYP19A1-inhibitor exemestane on the emergence of pre-antral follicles during culture to equalize the use of cOVA and tOVA. We compared follicular growth, morphology, and distribution between cOVA and tOVA using immunofluorescence and hormonal quantification. The inhibitor reduced the estrogen levels in both OVA types, while enhancing follicular morphology of tOVA. Moreover, treatment with exemestane decreased STAR expression in tOVA regulating progesterone locally. The addition of exemestane during this initial culture period may prove beneficial to obtain pre-antral follicles from tOVA more comparable to cOVA. These findings represent a step toward optimizing culture conditions to support early folliculogenesis.