Developing a strategy to promote perinatal health requires incorporating all current knowledge regarding the impact of early-life experiences and environments on adult health. The body’s development is subject to these various influences starting in the fetal stage. Preparing for the experience of “becoming a parent” requires an awareness of how individual life trajectories influence the health of the adult who becomes a parent. Reducing sources of toxic stress, regardless of their origin, is at the heart of this strategy. It is on these foundations of generational and intergenerational transmission that the parenting experience can be built to benefit the health of the baby and the adult they will become.