LAUSR

Timely and appropriate medical care can significantly influence the health of a newborn. When considering how to best deliver such care, we must first note that each human represents the result of a balance between nature (genetics) and nurture (environment). Importantly, while most of our care is centered on in utero development, the preconception period is also a time at which genetic and environmental factors can interact to exert effects that ultimately influence the health of the future offspring. In this issue's Views and Reviews, we provide data to suggest that modern preconceptional care should become a key component of reproductive medicine, not only to improve implantation and pregnancy rates, but also to reduce perinatal morbidity and mortality, further optimizing the health for mothers and children and setting the stage for the child's adult life. The preconception period should be regarded as an actionable "window of opportunity" for child health promotion, not only because of this gene-environment interaction and the opportunity to identify women's genetic risks, but also because it represents a time when women are most willing to abandon unhealthy habits.