Myo-Inositol to D-Chiro-Inositol Ratio in Follicular Fluid Plays a Pivotal Role for Oocyte and Embryo Quality: Summary of Available Evidence

The document highlights the importance of the Myo-Inositol (MI) to D-Chiro-Inositol (DCI) ratio in follicular fluid (FF) for the maturation of oocytes and the quality of embryos. Myo-Inositol, a vitamin B-complex group member, is crucial for proper folliculogenesis and has been used to treat various conditions, including polycystic ovary syndrome (PCOS). The paper discusses how in women with PCOS, there is a significant imbalance in the MI/DCI ratio in FF, leading to MI deficiency and impaired FSH signaling, which results in reduced oocyte quality. Studies have shown that the MI-DCI ratio in FF drops dramatically in patients with PCOS, who also have higher levels of insulin resistance and hyperinsulinemia. Furthermore, high doses of orally administered DCI correlate with a higher number of immature oocytes and a lower number of high-grade embryos. Conversely, a high MI/DCI ratio in FF can improve the quality of blastocysts and IVF outcomes. The conclusion is that the MI/DCI ratio in FF is critical for oocyte and embryo quality.