ABSTRACT: Recurrent pregnancy loss (RPL) remains a difficult and upsetting condition that affects women of reproductive age all over the world. With an emphasis on women in Kazakhstan, this study investigates the relationship between maternal body mass index (BMI) and RPL. The purpose of this study was to explore how maternal age and BMI relate to the risk of recurrent pregnancy loss, and to see whether these two factors might interact and influence each other. We found that the chances of experiencing RPL went up with age, especially for women 35 and older. Weight also played a role, both women who were underweight and those who were obese had a higher likelihood of experiencing repeated losses compared to those in a healthy BMI range. The highest risk was among women who were both older and obese, suggesting that these two factors may work together to increase the chances of RPL. Helping women maintain a healthy weight and encouraging earlier planning for pregnancy when possible could lower the risk of RPL, especially for those in higher-risk groups. These findings highlight the need for tailored treatment plans and preconception health optimization to enhance pregnancy outcomes for women at risk of RPL.