Magnesium (Mg2+) is an essential mineral that supports normal cellular metabolism, optimal musculoskeletal and neuronal functions, the immune response, and cardiovascular health. The regulation of magnesium is a complex process, and during pregnancy, it becomes even more challenging because of increased magnesium needs. Magnesium inadequacy during pregnancy can lead to severe complications, including preeclampsia in the mother, intrauterine growth restriction, preterm birth, low birth weight, insulin resistance, heart disease, and developmental delays in the neonate, due in part to its critical role in fetal musculoskeletal and nervous development. Magnesium deficiency during pregnancy is a global health concern, and raising awareness about the importance of maintaining magnesium balance, improving dietary intake, and promoting supplementation, when needed, could help reduce associated risks. This chapter discusses the impact of altered magnesium homeostasis on maternal health and fetal development while also addressing the need for global awareness and interventions to improve maternal and child health.