It seems to be that out of the four factors, including the three 'other factors' below, aclohol consumption is actually the least influential factor.
"Mother and child factors: mother?s age at the time of birth, number of children in the household, whether the pregnancy was planned, whether the mother smoked during pregnancy, birth weight and current age.
Socioeconomic factors: highest parental occupation, highest parental educational qualification, and family income.
Family psychosocial markers: mother?s current mental health, parental discipline, child made to follow instructions, mother?s parenting competence, closeness of relationship between mother and child and whether or not the mother currently drank alcohol."
It even says that light drinkers are disproportionately wealthy. I don't think the findings can be accurately used to show the effects of drinking in pregnancy. And, I don't understand how not drinking in pregnancy can have a more detrimental effect? How? What causes it? Other than the fact that the children of light drinkers are more likely to be born into wealthier families?