The physiological and social demands of pregnancy are immense. A period of transformation that tests a woman's body and resilience in profound ways. Yet, this time of vulnerability also offers an unparalleled opportunity to understand and improve women's health across the life course. Environmental change including rising temperatures, air and water pollution, and extreme weather events is now emerging as a major stressor during this critical life stage, shaping both immediate pregnancy outcomes and long-term health trajectories for mothers and their children. Women and girls are disproportionately affected by environmental hazards. Biological factors such as hormonal and thermoregulatory changes interact with entrenched social and economic inequities --- limited access to healthcare, insecure housing, unpaid care responsibilities, and occupational exposures --- to heighten risk. For pregnant women in particular, exposure to extreme heat has been linked to complications such as preterm birth, l