AOR95 % CI p valueNAOR95 % CI p value N AOR95 % CI p value N AOR95 % CI p value N AOR95 % CI p value N AOR95 % CI p valueParticipants597626582571646626 Maternal age <30 years209Reference218Reference219Reference191Reference212Reference207Reference30-34 years2281.11(0.68-1.82)0.672421.46(0.92–2.32)0.112090.90(0.51–1.61)0.732291.62(0.91–2.90)0.102471.51(0.91–2.50)0.11264 2.58 (1.54–4.31) <0.001 > = 35 years1601.23(0.71–2.11)0.461661.33(0.81–2.21)0.261540.95(0.52–1.74)0.881511.19(0.62–2.28)0.601871.58(0.94–2.68)0.091551.16(0.64–2.13)0.62 Pregnancy planning Yes476Reference502Reference438Reference456Reference526Reference491ReferenceNo1211.67(1.02–2.73)0.041241.32(0.83–2.11)0.25144 4.94 (2.98–8.20) <0.001 1151.83(1.05–3.20)0.031201.07(0.63–1.81)0.81135 2.00 (1.19–3.37) <0.01 Parity > = 1321Reference331Reference296Reference326Reference366Reference324Reference02761.21(0.79–1.85)0.372951.33(0.90–1.96)0.15286 2.04 (1.25–3.33) <0.01 2450.54(0.33–0.90)0.022800.68(0.45–1.04)0.073021.30(0.84–2.03)0.24 Smoking No533Reference538Reference499Reference502Reference550Reference519ReferenceYes640.50(0.23–1.13)0.10881.78(1.05–3.00)0.03831.62(0.88–2.98)0.12691.69(0.81–3.52)0.1796 3.62 (2.07–6.33) <0.001 107 3.80 (2.20–6.55) <0.001 Perceived alcohol effect Normal236Reference258Reference250Reference224Reference291Reference283ReferenceVery/quickly3090.75(0.49–1.14)0.173140.64(0.44–0.94)0.02276 0.30 (0.18–0.50) <0.001 3000.78(0.49–1.24)0.29297 0.33 (0.21–0.50) <0.001 280 0.25 (0.15–0.40) <0.001 Very/slowly520.62(0.27–1.39)0.26540.68(0.32–1.43)0.31560.90(0.41–1.96)0.78470.48(0.15–1.48)0.20580.96(0.46–2.02)0.92631.41(0.71–2.82)0.33 Household income <$40,00094Reference93Reference88Reference84Reference87Reference82Reference$40–100,0002790.71(0.40–1.27)0.252971.08(0.61–1.92)0.792700.91(0.44–1.88)0.812711.10(0.53–2.28)0.793031.43(0.73–2.81)0.302882.59(1.12–5.98)0.03>$100,0001970.88(0.47–1.63)0.672111.46(0.79–2.67)0.231991.75(0.83–3.70)0.141931.56(0.73–3.31)0.252281.89(0.93–3.84)0.08229 4.16 (1.77–9.77) <0.01 Missing270.84(0.29–2.40)0.74250.69(0.21–2.29)0.54250.68(0.18–2.63)0.58230.56(0.11–2.90)0.49281.80(0.57–5.66)0.31273.08(0.84–11.27)0.09 BMI Norma371Reference384Reference342Reference357Reference418Reference391ReferenceOverweight1160.86(0.51–1.46)0.571210.85(0.52–1.40)0.531251.71(0.99–2.95)0.051120.77(0.43–1.37)0.371200.63(0.38–1.05)0.081240.77(0.45–1.33)0.35Obese1100.66(0.36–1.19)0.161210.72(0.44–1.20)0.211150.84(0.45–1.59)0.601020.41(0.20–0.86)0.02108 0.28 (0.15–0.53) <0.001 111 0.42 (0.23–0.79) <0.01 Maternal education Secondary111Reference123Reference110Reference104Reference117Reference120ReferenceTrade/Diploma1540.81(0.42–1.58)0.541781.03(0.60–1.77)0.931711.93(0.96–3.86)0.061481.07(0.48–2.38)0.871681.06(0.56–2.01)0.851650.86(0.45–1.64)0.64Tertiary3321.45(0.79–2.66)0.233250.89(0.52–1.54)0.683011.54(0.75–3.17)0.243192.48(1.18–5.23)0.02361 2.21 (1.21–4.04) 0.01 3411.42(0.77–2.61)0.26 Ethnicity White455Reference489Reference460Reference447Reference527Reference506ReferenceAsian/other1420.82(0.49–1.37)0.451370.65(0.39–1.08)0.10122 0.33 (0.16–0.71) <0.01 124 0.36 (0.18–0.71) <0.01 119 0.11 (0.05–0.25) <0.001 120 0.14 (0.06–0.32) <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 missing data)AOR (95 % CI): Odds ratio and 95 % confidence interval adjusted for all predictors shown in table. Control group is abstinence in pregnancy, but not lifetime abstainer. Results are in bold font where a significant difference was found. For
