The relationship in women between genetic liability and the risk of onset of alcohol use disorder while pregnant or rearing an infant, toddler, or preschool child.

While pregnancy clearly reduces the risk for Alcohol Use Disorder (AUD) onset, we know less about the impact on AUD risk of having young children and how these effects vary across maternal age and level of maternal AUD genetic risk. Therefore, in 1.2 million parous Swedish women born 1960-1995, we examined those with a first registration for AUD between ages 15-40 while first pregnant, or while raising their first infant (aged 0-12 months), toddler (13-36 months) or preschooler (37-60 months). Genetic risk for AUD was assessed by their family genetic risk score. Pregnancy and having an infant consistently reduced AUD risk with the protective effect becoming stronger with increasing maternal genetic risk. Raising a toddler was modestly protective, but unrelated to genetic risk. Raising a preschooler, while unrelated to AUD risk in mothers with low genetic liability, in those at higher genetic liability increased AUD risk considerably. These effects varied substantially across maternal age. Being pregnant or having an infant were only marginally protective in teenage mothers. Compared to older mothers, younger mothers were considerably more sensitive to the predisposing effects on AUD risk of toddlers and preschoolers. The effects of pregnancy and rearing young children were muted at older maternal ages. We conclude that the risk for AUD mothers while pregnant or rearing small children varies substantially as a function of the age of the child, the genetic risk of the mother and the mother's age. These risk and protective factors can interact substantially with one another.