The main analyses consisted of linear regression models examining the association between the consumption of ≥4 drinks in a day on at least one occasion (yes/no; main exposure) at either measured time point during pregnancy and child SDQ and KS2 outcomes at age 11. The sample was restricted to the 7,965 children whose mothers provided information on alcohol use at both 18 and 32 weeks gestation. Regression estimates were adjusted for the potential confounding effect of the prenatal variables as well as child factors listed above using multivariable regression modelling. Based on our earlier work [18], the following additional steps were carried out:We identified the relationships between the main exposure (≥4 drinks per day) and the prenatal maternal and socio-demographic and child variables outlined above (Table 1).Table 1Correlates of consuming ≥4 drinks in a day during pregnancy<4 drinks a day n = 6044≥4 drinks a day n = 1921 χ 2 (1 d.f.) p Prenatal factors Maternal age (≥35 years)10 %11 %1.560.211 Any smoking15 %30 %209.44<0.001 Cannabis use1 %4 %62.41<0.001 Other illicit drug use0.3 %0.8 %7.200.007 Parity (≥1)54 %61 %26.34<0.001
