(13.0 %). Approx 67 % of missing data was amongst the women abstaining in pregnancy cPearson chi square, p valueT1, T2, T3: Trimesters 1, 2 and 3Table 4Predictors of pregnancy alcohol use: Tiers 1 and 2PAE tier 1PAE tier 2PAEAny alcohol in pregnancya Abstinent after trimester 1a Drank throughouta N AOR95 % CI p value N AOR95 % CI p value N AOR95 % CI p valueParticipants1318873911 Maternal age <30 years421Reference312Reference276Reference 30–34 years5391.40(1.04–1.88)0.033271.13(0.81–1.59)0.47388 1.85 (1.29–2.66) <0.01 > = 35 years3581.28(0.92–1.77)0.142341.18(0.81–1.71)0.392471.37(0.92–2.05)0.12 Pregnancy planning Yes1004Reference662Reference719Reference No314 1.89 (1.40–2.55) <0.001 211 2.05 (1.47–2.87) <0.001 1921.60(1.10–2.33)0.01 Parity > = 1689Reference438Reference506Reference 06291.03(0.80–1.33)0.804351.39(1.04–1.86)0.034050.75(0.55–1.03)0.08 Smoking No1091Reference750Reference751Reference Yes227 1.94 (1.36–2.77) <0.001 1231.33(0.88–2.02)0.17160 3.05 (2.00–4.67) <0.001 Perceived alcohol effect Normal652Reference388Reference442Reference Very/quickly551 0.47 (0.37–0.61) <0.001 409 0.58 (0.44–0.78) <0.001 387 0.38 (0.28–0.52) <0.001 Very/slowly1150.78(0.50–1.20)0.26760.74(0.44–1.24)0.25820.89(0.52–1.53)0.68 Household income <$40,000168Reference131Reference109Reference $40–100,0005781.16(0.80–1.68)0.443940.93(0.62–1.42)0.754101.53(0.94–2.51)0.09 >$100,000522 1.71 (1.15–2.54) <0.01 3131.32(0.84–2.05)0.23356 2.43 (1.45–4.04) <0.01 Missing500.96(0.48–1.90)0.91350.75(0.34–1.66)0.48361.57(0.65–3.79)0.31 BMI Normal853Reference533Reference602Reference Overweight2580.87(0.63–1.18)0.371781.03(0.72–1.47)0.871720.70(0.48–1.03)0.07 Obese207 0.53 (0.38–0.75) <0.001 1620.76(0.52–1.11)0.16137 0.35 (0.22–0.54) <0.001 Maternal education Secondary230Reference162Reference159Reference Trade/Diploma3391.04(0.72–1.50)0.842451.10(0.73–1.67)0.652230.99(0.62–1.58)0.98 Tertiary7491.48(1.04–2.11)0.034661.22(0.81–1.84)0.35529 1.88 (1.21–2.93) <0.01 Ethnicity White1109Reference694Reference770Reference Asian/other209 0.38 (0.27–0.52) <0.001 179 0.61 (0.42–0.88) <0.01 141 0.19 (0.12–0.30) <0.001 N: Sample size for multivariate analysis (i.e. number of cases with a complete set of predictors, except for income, where a ‘missing’ category was included because ~ 4 % of
