Myo-Inositol and Its Derivatives: Their Role in the Challenges of Infertility

Myo-inositol (MYO) and D-chiro-inositol (DCI) are the two most significant isomeric forms of inositol, playing a critical role in intracellular signaling. MYO is the most abundant form of inositol in nature; DCI is produced from MYO through epimerization by an insulin-dependent enzyme. Recently, it has been demonstrated that inositols may influence oocyte maturation, improve intracellular Ca2+ oscillation in the oocytes and have been proposed as potential interventions for restoring spontaneous ovulation. MYO concentration in human follicular fluid is considered a bioindicator of oocyte quality. In the ovary, DCI modulates the activity of aromatase thus regulating androgen synthesis. Under physiological conditions, MYO/DCI ratio is maintained at 40:1 in the plasma. In women with PCOS, MYO/DCI ratio lowers to 0:2:1, contributing to elevated androgen production. By regulating FSH signaling, MYO administration increases the number of high-quality embryos available for transfer in poor responder patients. Finally, by acting downstream to insulin signaling inositol administration during pregnancy may represent a novel strategy for counteracting gestational diabetes. These findings show that diet supplementation with inositols may be a promising strategy to address female infertility and sustain healthy pregnancy.