High maternal stress during pregnancy is a risk factor for preterm birth and low birthweight, which endanger infant, child, and adult health and development. Interventions to alleviate the conditions that contribute to pregnant women's stress and to diminish its harmful consequences can target both societal and individual levels. Policy-relevant examples include: expanding healthcare access and screening to identify women experiencing high stress or engaged in risky behaviors, reducing the prevalence of unintended pregnancy and widening access to abortion, improving the living conditions of women in under-resourced communities, diversifying and training healthcare providers to reduce discriminatory treatment of pregnant women of color, and ensuring paid maternal leave and affordable childcare for all. Measures that alleviate stress and its harms to pregnancy promote healthier outcomes for mothers and babies and benefit society at large.