Importantly, these mechanistic disruptions translated into measurable clinical effects across the included trials: reductions in insulin resistance (e.g., decreased HOMA-IR and fasting insulin) were consistently associated with improved ovulation and conception rates, while adverse metabolic profiles such as metabolic syndrome and hyperhomocysteinemia correlated with lower oocyte yield, increased miscarriage risk, and reduced live birth outcomes. Here, INS is linked to spontaneous abortion.