Table 1.
Descriptive Statistics for Risk Factors, Birth Weight, and Genetic Instruments in DNBC
| Variable | Description | Mean | Std. Dev. |
N |
|---|---|---|---|---|
| Smoking | 0/1 indicator for any smoking during pregnancy |
0.280 | 0.449 | 1900 |
| Cigarettes | Average number of cigarettes smoked per day |
1.541 | 3.757 | 1813 |
| BMI | Maternal body mass index | 23.527 | 4.308 | 1811 |
| Obese | 0/1 indicator for obese mothers (BMI >30) |
0.087 | 0.282 | 1811 |
| Birth weight | Child birth weight in grams | 3095.077 | 871.277 | 1914 |
| rs12914385 | Number of T alleles of maternal rs12914385 in CHRNA3 |
0.749 | 0.685 | 1934 |
| rs8050136 | Number of A alleles of maternal rs8050136 in FTO |
0.799 | 0.692 | 1937 |