A Hyperandrogenic Environment Causes Intrinsic Defects That Are Detrimental to Follicular Dynamics in a PCOS Mouse Model.

Polycystic ovary syndrome (PCOS) is a common cause of female infertility. Hyperandrogenism is both a major symptom and key diagnostic trait of PCOS; however, the direct impact of this androgen excess on ovarian dynamics is unclear. By combining a DHT-induced PCOS mouse model with an ex vivo follicle culture system, we investigated the impact of hyperandrogenism on ovarian function. Ovaries from PCOS mice exhibited the characteristic polycystic ovary morphology with numerous large cystic follicles and no corpora lutea present. Isolation and individual culture of preantral and antral follicles from PCOS mice resulted in slower growth rates during 5 days compared with the follicles isolated from control mice (P < 0.01). In contrast, preovulatory follicles from PCOS mice exhibited a significant increase in growth rate compared with controls (P < 0.01). Preantral follicles from PCOS ovaries maintained comparable follicular health as control follicles, but antral and preovulatory PCOS follicles exhibited reduced follicle health (P < 0.01) and survival rates (P < 0.01). Compared with controls, PCOS females also exhibited a poorer response to hyperstimulation (P < 0.01), impaired oocyte function evident by increased levels of reactive oxygen species (P < 0.01), and a reduction in on-time embryo development (P < 0.01). These results demonstrate that prolonged exposure to androgen excess leads to aberrant follicle development, which persists even after removal from the hyperandrogenic environment, causing perturbed follicular developmental trajectories. These findings indicate that an in vivo hyperandrogenic environment in patients with PCOS may intrinsically induce detrimental effects on follicles and oocytes.