Table 1.
Variable | Definition | Mean (SD) |
---|---|---|
Cigarettes before pregnancy | Number of cigarettes per day smoked in the 12 months before pregnancy | 4.2 (6.4) |
Cigarettes in the first trimester | Number of cigarettes per day smoked in the first trimester | 2.3 (4.3) |
Maternal age | Maternal age in years | 29.3 (4.7) |
Less than high schoola | Binary (0,1) indicator for maternal education of less than completed high school | 0.111 (0.314) |
High schoola | Binary (0,1) indicator for maternal education of completed high school | 0.255 (0.436) |
Technical collegea | Binary (0,1) indicator for mother attending technical college | 0.202 (0.402) |
Universitya | Binary (0,1) indicator for mother completing university education | 0.064 (0.245) |
Maternal employment | Binary (0,1) indicator for maternal employment in the first trimester | 0.839 (0.368) |
Very low maternal incomeb | Binary (0,1) indicator for current gross maternal yearly income of less than 150,000 kr | 0.359 (0.48) |
Moderate maternal incomeb | Binary (0,1) indicator for current gross maternal yearly income between 201,000 and 250,000 kr inclusive | 0.244 (0.43) |
High maternal incomeb | Binary (0,1) indicator for current gross maternal yearly income of 251,000 kr or more | 0.141 (0.349) |
Binge drinking in the first trimesterc | Binary (0,1) indicator for ≥ 4 drinks per drinking occasion in the first trimester | 0.06 (0.237) |
Moderate drinking in the first trimesterc | Binary (0,1) indicator for 2–3 drinks per occasion in the first trimester | 0.092 (0.29) |
Low drinking in the first trimesterc | Binary (0,1) indicator for 1 drink per occasion in the first trimester | 0.189 (0.392) |
Multivitamin use | Binary (0,1) indicator for using multivitamins before and during the first two months of pregnancy | 0.359 (0.48) |
Underweightd | Binary (0,1) indicator for maternal BMI prior to pregnancy of less than 18.5 | 0.03 (0.172) |
Overweightd | Binary (0,1) indicator for maternal BMI prior to pregnancy between 25 and 29.9 inclusive | 0.19 (0.393) |
Obesed | Binary (0,1) indicator for maternal BMI prior to pregnancy of greater than 29.9 | 0.079 (0.271) |
Calories | Average daily calorie intake during the first trimester | 2244.6 (750.8) |
Pregnancy planning | Binary (0,1) indicator for mothers who were planning to become pregnant | 0.735 (0.442) |
rs1930139_BBe | Binary (0,1) indicator of AB genotype of rs1930139 | 0.327 (0.469) |
rs1930139_ABe | Binary (0,1) indicator of BB genotype of rs1930139 | 0.051 (0.221) |
rs1547272_BBe | Binary (0,1) indicator of AB genotype of rs1930139 | 0.345 (0.476) |
rs1547272_ABe | Binary (0,1) indicator of BB genotype of rs1930139 | 0.06 (0.237) |
rs1435252_AAf | Binary (0,1) indicator of AB genotype of rs1435252 | 0.082 (0.274) |
rs1435252_ABf | Binary (0,1) indicator of BB genotype of rs1435252 | 0.405 (0.491) |
rs2743467_BBe | Binary (0,1) indicator of AB genotype of rs2743467 | 0.43 (0.495) |
rs2743467_ABe | Binary (0,1) indicator of BB genotype of rs2743467 | 0.11 (0.313) |
Note: The sample includes 856 observations.
The reference category is 2–4 years of college;
The reference category is 151,000–200,000 kr;
The reference category is no drinking;
The reference category is normal weight (18.5≤BMI<25);
The reference category for the SNP genotype indicators is the AA genotype;
The reference category for the SNP genotype indicator is the BB genotype.