Table 1 Basic characteristics (total n = 44,747)
Frequency of SHS exposure before pregnancy | ||||
|---|---|---|---|---|
rarely | 1–3 days/week | 4–7 days/week | ||
(n = 27,097) | (n = 10,585) | (n = 7065) | ||
Duration of SHS exposure (/day)(%) | ||||
<1 h | 99.91 | 84.38 | 71.86 | |
1–2 h | 0.06 | 11.78 | 15.92 | |
≥2 h | 0.03 | 3.84 | 12.22 | |
Participant’s background | ||||
Age (years) | ||||
mean (SD) | 32.15 (4.55) | 30.99 (4.83) | 30.28 (5.36) | |
<20 | 0.17 | 0.44 | 1.76 | |
20–24 | 4.24 | 8.27 | 12.92 | |
25–29 | 24.93 | 31.32 | 30.62 | |
30–34 | 39.20 | 35.22 | 31.82 | |
35–39 | 26.15 | 20.69 | 18.70 | |
≥40 | 5.31 | 4.06 | 4.19 | |
Primipara (%) | 39.90 | 50.63 | 53.76 | |
BMI before pregnancy (kg/m2) (%) | ||||
mean (SD) | 20.91 (2.92) | 21.17 (3.16) | 21.34 (3.37) | |
<18.5 | 16.75 | 15.95 | 15.07 | |
18.5–24.9 | 75.15 | 74.13 | 73.55 | |
≥25.0 | 8.10 | 9.92 | 11.38 | |
Weight gain during pregnancy (kg) (SD) (n = 43,732) | 9.78 (6.38) | 9.92 (3.69) | 10.17 (3.97) | |
Alcohol consumption at entry (%) | ||||
no drinking | 42.19 | 38.45 | 39.35 | |
quit before or during pregnancy | 47.96 | 50.77 | 50.30 | |
continued drinking | 9.85 | 10.78 | 10.35 | |
K6 score ≥13 (%) | 2.35 | 2.72 | 3.77 | |
Educational level (%) | ||||
junior high school | 0.69 | 1.62 | 3.35 | |
high school | 19.14 | 25.73 | 37.58 | |
college | 80.17 | 72.66 | 59.07 | |
Family income (JPY) (%) | ||||
<200 × 104 | 2.53 | 4.48 | 7.30 | |
200–399 × 104 | 27.36 | 32.10 | 38.94 | |
400–599 × 104 | 35.38 | 34.08 | 30.66 | |
600–799 × 104 | 20.23 | 17.38 | 13.80 | |
≥800 × 104 | 14.50 | 11.96 | 9.30 | |
Sodium intake (mg/day) | median (inter quartile range) | 2836 (2150–3728) | 2887 (2158–3864) | 2902 (2117–3944) |
Pottasium intake (mg/day) | median (inter quartile range) | 2131 (1624–2812) | 2116 (1590–2826) | 2075 (1505–2792) |
Calcium intake (mg/day) | median (inter quartile range) | 471 (332–656) | 459 (321–648) | 439 (294–634) |
Magnecium intake (mg/day) | median (inter quartile range) | 222 (173–287) | 221 (171–289) | 217 (162–284) |
Salt intake (g/day) | median (inter quartile range) | 7.1 (5.4–9.8) | 7.3 (5.4–9.8) | 7.3 (5.3–9.9) |
Total Energy intake (kJ/day) | median (inter quartile range) | 7029 (5809–8626) | 7194 (5847–8860) | 7140 (5721–9022) |
History of HDP (%) | 1.16 | 1.21 | 1.05 | |
History of GDM (%) | 0.64 | 0.43 | 0.57 | |
Patner’s Background | ||||
Partner’s smoking before pregnancy (%) | ||||
no smoking | 43.64 | 31.11 | 17.31 | |
quit before pregnancy | 30.36 | 23.09 | 13.43 | |
quit during pregnancy | 1.41 | 2.28 | 2.36 | |
continued smoking | 24.59 | 43.52 | 66.89 | |
Partner’s educational level (%) | ||||
junior high school | 2.03 | 4.09 | 8.63 | |
high school | 27.20 | 33.25 | 42.25 | |
college | 70.77 | 62.66 | 49.12 | |
Outcome | ||||
Prevalence of HDP (%) | 2.58 | 2.96 | 3.47 | |
