# Table 2 Results of included studies

Author, year Sampling frame Characteristics of mothers N exposed N exposed with outcome N controls N controls with outcome Odds ratios/Mean (95% CI)
O’Leary et al. 2009 [30] Population-based sample from all women giving birth in Australia 1995 to 1997 Age      Unadjusted
<25: 32.7% Trimester 1: 544 Trimester 1: 79 Trimester 1: 934 Trimester 1: 126 Trimester 1: 0.95 (0.68 to 1.34)
25 to 29: 13.0% Trimester 2: 609 Trimester 2: 73 Trimester 2: 946 Trimester 2: 123 Trimester 2: 0.88 (0.63 to 1.23)
>30: 54.5% Trimester 3: 665 Trimester 3: 77 Trimester 3: 870 Trimester 3: 113 Trimester 3: 0.83 (0.6 to 1.17)
<12 years: 40.6%      Trimester 1: 0.97 (0.65 to 1.43)
>12 years: 24.4%      Trimester 2: 0.87 (0.59 to 1.28)
Degree\Diploma\Trade: 34.8%      Trimester 3: 0.84 (0.57 to 1.23)
Smoking      Explanation: Data show unadjusted and confounder adjusted odds ratios for the probability of language delay among low drinkers compared to women who are abstinent at the same time point. All results show reduced odds among low drinkers but results are not statistically significant as indicated by the confidence intervals which span the null value of an odds ratio equal to 1.
Pre-pregnancy: 27.0%
Parity
Primiparous: 29.8% 1: 30.2%
>2: 40.0%
Marital status
Married: 79.2%
Cohabiting: 15.4%
Single: 5.4%
Illicit Drug use: 12.5%
Faden and Graubard 2000 [29] Population based sample from national birth certificate in the United States NR* NR* Language Outcome (Low to High) NR* NR* Mean (95% CI)
1/7 = 136    0/7 = 0.47 (0.37)
2/7 = 267    1/7 = 1.64 (1.28)
3/7 = 493    2/7 = 0.23 (0.10)
4/7 = 855    3/7 = 0.57 (0.17)
5/7 = 1323    4/7 = 0.58 (0.12)
6/7 = 1969    5/7 = 0.57 (0.09)
7/7 = 2851    6/7 = 0.74 (0.14)
7/7 = 0.65 (0.10)
Explanation: Data show mean number of drinks per day for scores of 0 to 7 (low to high levels of language development) on the seven-point Denver Language Development scale.
Greene et al. 1990 [31] Hospital based Race Black: 31.5% 179 at 1 year 1 year 1 year: 93 1 year: 93 Expressive Language
Age (mean (SD)): 22.1 (4.4)   1/3 drink per day:139    Mean (95% CI)
Parent education in years (mean (SD)): 10.8 (1.4)   >1/3 to 1.5 drinks per day: 40    1 year
Cigarette use in pregnancy (mean (SD)): 13.8 (12.2) 142 at 2 years 2 years 2 year: 94 2 year: 94 A) 25.5 (25.0 to 26.5)
Prenatal marijuana: 35.1%   l2 years    B) 26.0 (25.0 to 27)
Prenatal street drugs: 9.2%   1/3 drink per day:136    2 year
1/3 to 1.5 drinks per day: 36    A) 30.0 (28.5 to 31.0)
171 at 3 years 3 years 3 year: 92 3 year: 92 B) 29.0 (27.0 to 32.0)
1/3 drink per day: 132    3 years
1/3 to 1.5 drinks per day: 39    A) 30.0 (28.0 to 32.0)
Receptive language
B) 31.0 (28.0 to 34.0)
1 year
B) 24.0 (22 to 25)
A) 24.0 (23 to 25)
2 years
A) 39.0 (37.0 to 40.0)
B) 38.0 (36.0 to 40.0)
3 years
A) 24.0 (23.0 to 25.0)
B) 25.0 (23.0 to 27.0)
Explanation: Mean age-adjusted SICD scores for Expressive and Receptive language development at 1, 2 and 3 years for A) 1/3 drink per day and B) >1/3 to 1 and 1/2 drinks per day compared to abstinence.
1. *Not reported.