The emerging role of angiogenic factor dysregulation in the pathogenesis of polycystic ovarian syndrome.

Polycystic ovarian syndrome (PCOS) is a common endocrine disorder in reproductive age affecting 5 to 7% of women. It is characterized by anovulatory infertility, hyperandrogenism, and polycystic ovaries. Angiogenesis in the ovary is critical for follicular growth, ovulation, and the subsequent development and regression of the corpus luteum. Accumulating evidence suggests that multiple angiogenic factors are dysregulated in PCOS, including vascular endothelial growth factor, angiopoietins, platelet-derived growth factor, transforming growth factor-β, and basic fibroblast growth factor. This angiogenic factor imbalance likely underlies the increased stromal vascularity observed in PCOS. Angiogenic factor dysregulation may play an important role in the pathophysiology of PCOS and may contribute to ovulatory dysfunction, subfertility, and ovarian hyperstimulation syndrome, which are commonly seen in women with PCOS. Further experimental studies are needed to gain a better understanding of the growth factors that are involved in normal and pathological ovarian angiogenesis, and to assess the potential of angiogenesis-based treatment strategies in PCOS.