T2, T3: Trimesters 1, 2 and 3Table 3Relationship between early maternal age at onset of drinking and first intoxication and pregnancy alcohol consumption patternsAge at drinking regularlya Age first intoxicatedb > = 18 yrs<18 yrsp chi2c > = 18 yrs<18 yrsP chi2c Total number of participants626 (%)489 (%)554 (%)651 (%)Abstinent throughout pregnancy181 (28.9)133 (27.2)Reference211 (38.1)164 (25.2)ReferencePAE tier 1Drank alcohol while pregnant445 (71.1)356 (72.8)0.53343 (61.9)487 (74.8)<0.001PAE tier 2Drank alcohol in trimester one only220 (35.1)150 (30.7)0.63186 (33.6)196 (30.1)0.04Drank alcohol throughout pregnancy225 (35.9)206 (42.1)0.14157 (28.3)291 (44.7)<0.001PAE tier 3Low in T1, abstinent in T2 and T368 (10.9)37 (7.6)0.2059 (10.6)52 (8.0)0.56Moderate/high in T1, abstinent in T2 and T386 (13.7)68 (13.9)0.7176 (13.7)78 (12.0)0.15Binge preaware, abstinent in T2 and T366 (10.5)45 (9.2)0.7451 (9.2)66 (10.1)0.02Low in T1, low/moderate in T2 and/or T358 (9.3)37 (7.6)0.5657 (10.3)47 (7.2)0.79Moderate/high in T1, any level in T2 and/or T392 (14.7)83 (17.00.2864 (11.6)117 (18.0)<0.001Binge pre-aware, low/moderate in T2 and/or T375 (12.0)86 (17.6)0.0236 (6.5)127 (19.5)<0.001 amissing data on 270 (19.5 %) bmissing data on 180 (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
