No longer is cardiovascular health understood to be only affected by exposures near in time to clinical outcomes. Maternal preconception health has been studied as a contributor to offspring health, although differentiating preconception from pregnancy exposures and shared environmental and genetic risks is difficult. Congenital heart disease, the most common form of heart disease in children, is predicted by maternal preconception diabetes, hypertension, and obesity. Preconception diabetes and obesity have also been associated with offspring heart structure. Maternal preconception obesity is associated with offspring metabolic changes, diabetes, blood pressure, and reduced physical fitness. Both maternal and paternal smoking have been associated with congenital heart disease and offspring higher body mass index (BMI) and obesity. Other preconception exposures, such as social determinants and environmental pollutants, have not been studied to any great extent. When preconception risk factors are considered not as an independent, causal risk factor and more as an indicator of early-life risk, it suggests that improvement of cardiovascular health in young adulthood will improve population health in the next generation.