Figure 1: Adolescence and the next generation: a model of processes underpinning intergenerational transmission.
Puberty marks a transition to adolescence and a life phase during which girls and boys acquire resources that are essential for becoming parents of the next generation. It also marks the beginning of reproductive life with a transition to functional gamete production. The preconceptional phase (that is, adolescence) varies markedly in length carrying implications for the acquisition of the social, financial and educational assets and nutritional, health and interpersonal risks that underlie intergenerational processes. The three months before conception is a time of male and female gamete maturation when parental exposures, including nutrition, obesity, substance use, stress, endocrine disruptors and physical activity may influence gamete structure and function. Periconception includes fertilization of the maternal and paternal gametes as well as the zygote and embryonic phases that are sensitive to the maternal nutritional and hormonal environment. There continue to be direct maternal effects antenatally mediated through the in utero environment and postnatally through nutrition (for example, breastfeeding) and the maternal–infant relationship. Direct paternal influences grow in the postnatal phase through the paternal–infant relationship and potentially through risk exposures, such as paternal tobacco use. Maternal and paternal health, behaviour as well as social and economic circumstances continue to have an indirect effect on offspring development in both antenatal and postnatal phases.
