Table 1 Characteristics of subjects (total = 76,303)
Smoking during pregnancy (n = 76,303) | P value | |||||
|---|---|---|---|---|---|---|
No smoking (n = 44,998) | Quit before pregnancy (n = 17,992) | Quit during pregnancy (n = 9899) | Continued smoking (n = 3414) | |||
Age (years) | ||||||
Mean (SD) | 31.58 (4.81) | 31.96 (4.72) | 29.60 (5.13) | 30.22 (5.46) | <0.01 | |
<20 | 0.49 | 0.17 | 1.34 | 1.26 | <0.01 | |
20–24 | 6.60 | 5.94 | 15.91 | 15.11 | <0.01 | |
25–29 | 27.36 | 24.63 | 33.43 | 29.76 | <0.01 | |
30–34 | 37.05 | 38.12 | 30.60 | 29.88 | <0.01 | |
35–39 | 23.66 | 25.99 | 16.02 | 19.65 | <0.01 | |
≥40 | 4.84 | 5.15 | 2.70 | 4.21 | <0.01 | |
Primipara (%) | 44.66 | 33.98 | 49.81 | 32.51 | <0.01 | |
BMI (kg/m2) (%) | ||||||
Mean (SD) | 21.04 (3.06) | 21.42 (3.33) | 21.36 (3.54) | 21.65 (3.92) | <0.01 | |
<18.5 | 16.30 | 13.98 | 17.30 | 18.16 | <0.01 | |
18.5–25 | 74.62 | 74.74 | 70.12 | 66.67 | <0.01 | |
≥25 | 9.08 | 11.28 | 12.58 | 15.17 | <0.01 | |
Weight gain during pregnancy (kg) (SD) Alcohol consumption during pregnancy (%) | 9.87 (5.50) | 10.25 (3.95) | 12.04 (4.54) | 11.22 (4.70) | <0.01 | |
No drinking | 40.84 | 24.95 | 25.65 | 24.11 | <0.01 | |
Quit before or during pregnancy | 49.01 | 62.53 | 67.74 | 64.91 | <0.01 | |
Continued drinking | 10.14 | 12.52 | 6.61 | 10.98 | <0.01 | |
Educational level (%) maternal | ||||||
Junior high school | 1.33 | 4.60 | 10.53 | 23.02 | <0.01 | |
High school | 23.66 | 35.04 | 46.36 | 49.15 | <0.01 | |
College | 75.01 | 60.35 | 43.12 | 27.83 | <0.01 | |
Partner | ||||||
Junior high school | 3.57 | 7.73 | 14.74 | 25.16 | <0.01 | |
High school | 31.04 | 39.81 | 48.67 | 49.44 | <0.01 | |
College | 65.38 | 52.46 | 36.59 | 25.40 | <0.01 | |
Smoking during pregnancy of partner (%) | ||||||
No smoking | 36.47 | 19.95 | 8.62 | 5.68 | <0.01 | |
Quit before pregnancy | 25.95 | 29.91 | 7.72 | 6.03 | <0.01 | |
Quit during pregnancy | 1.77 | 2.33 | 6.94 | 0.94 | <0.01 | |
Continued smoking | 35.80 | 47.80 | 76.72 | 87.35 | <0.01 | |
Family income (JPY) (%) | ||||||
<200 × 104 | 3.75 | 5.17 | 9.11 | 15.11 | <0.01 | |
200–399 × 104 | 30.34 | 36.44 | 44.70 | 45.72 | <0.01 | |
400–599 × 104 | 34.33 | 34.42 | 29.54 | 25.78 | <0.01 | |
600–799 × 104 | 18.52 | 14.46 | 10.49 | 8.47 | <0.01 | |
≥800 × 104 | 13.06 | 9.50 | 6.16 | 4.92 | <0.01 | |
K6 score ≥ 13 (%) | 2.66 | 3.07 | 5.34 | 7.23 | <0.01 | |
Prevalence of HDP (%) | 2.82 | 2.95 | 3.25 | 3.40 | 0.04 | |
