From: The Hokkaido Birth Cohort Study on Environment and Children’s Health: cohort profile—updated 2017
Follow-ups (n = 19,579) | Lost to follow-up (n = 1226) | Sub-cohort (n = 4869) | |||||||
---|---|---|---|---|---|---|---|---|---|
n | Mean or % | 95% CI | n | Mean or % | 95% CI | n | Mean or % | 95% CI | |
Maternal characteristics | |||||||||
Age at entry (years) | 19,549 | 29.9 | 29.8–29.9 | 1166 | 29.4 | 29.1–29.7 | 4831 | 29.9 | 29.8–30.0 |
Maternal body mass index | 18,428 | 21.2 | 21.1–21.2 | 1141 | 20.9 | 20.7–21.0 | 4608 | 21.2 | 21.1–21.3 |
Nulliparous (%) | 7226 | 42.1 | 41.4–42.9 | 595 | 54.5 | 51.5–57.4 | 1726 | 40.9 | 39.4–42.3 |
History of reproductive therapy (%) | 925 | 4.9 | 4.6–5.3 | 73 | 6.2 | 5.0–7.8 | 259 | 5.5 | 4.9–6.2 |
Regular use of any medicine (%) | 1956 | 10.3 | 9.8–10.7 | 139 | 11.3 | 9.7–13.2 | 519 | 11.0 | 10.1–11.9 |
Regular use of any supplement (%) | 5852 | 30.7 | 30.0–31.3 | 378 | 30.8 | 28.3–33.5 | 1565 | 33.1 | 31.8–34.5 |
Drinking habit at 1st trimester (%) | 2180 | 11.7 | 11.3–12.2 | 141 | 12.1 | 10.4–14.1 | 531 | 11.4 | 10.5–12.4 |
Smoking habit 1st trimester (%) | 2136 | 12.0 | 11.6–12.5 | 135 | 12.2 | 10.5–14.3 | 487 | 11.6 | 10.7–12.6 |
Passive smoking in house (%) | 11,752 | 65.9 | 65.2–66.6 | 687 | 61.2 | 58.3–64.0 | 2852 | 63.6 | 62.2–65.0 |
Education, compulsory education only (%) | 1011 | 5.4 | 5.1–5.7 | 74 | 6.4 | 5.1–7.9 | 247 | 5.3 | 4.7–6.0 |
Occupation, no job | 8137 | 41.6 | 40.9–42.3 | 499 | 40.7 | 38.0–43.5 | 2012 | 41.5 | 40.1–42.9 |
Income, <3,000,000 yen/year (%) | 3662 | 22.8 | 22.2–23.5 | 240 | 23.8 | 21.2–26.5 | 916 | 22.7 | 21.4–24.0 |
Paternal characteristics | |||||||||
Age at entry (years) | 18,311 | 31.7 | 31.6–31.8 | 1135 | 31.1 | 30.8–31.4 | 4595 | 31.7 | 31.5–31.9 |
Drinking habit (%) | 13,375 | 72.1 | 71.5–72.8 | 863 | 75.2 | 72.6–77.6 | 3319 | 71.5 | 70.2–72.8 |
Smoking habit 1st trimester (%) | 10,855 | 66.4 | 65.7–67.1 | 650 | 64.3 | 61.3–67.2 | 2644 | 65.0 | 63.5–66.4 |
Education, compulsory education only (%) | 1431 | 7.8 | 7.4–8.2 | 78 | 6.9 | 5.6–8.5 | 347 | 7.5 | 6.8–8.3 |
Occupation, no job | 417 | 2.2 | 2.0–2.4 | 41 | 3.4 | 2.6–4.7 | 117 | 2.5 | 2.0–3.0 |