Table 1.
Maternal blood PFOS and PFOA levels (ng/mL) in relation to the characteristics of the subjects participating in the Hokkaido Study on Environment and Children’s Health, Sapporo, Japan, 2002–2005 (n = 306).
| Characteristic | n (%) | PFOS [mean ± SD, median(25th–75th percentile),or correlationa (p-value)] | p-Valueb | PFOA [mean ± SD, median(25th–75th percentile),or correlationa (p-value)] | p-Valueb |
|---|---|---|---|---|---|
| Mean (± SD) | 306 (100.0) | 6.02 ± 2.67 | 1.52 ± 0.89 | ||
| Median (25th–75th percentile) | 306 (100.0) | 5.60 (4.0–7.5) | 1.40 (0.9–2.0) | ||
| Maternal characteristics | |||||
| Age (years) | |||||
| < 28 | 87 (28.4) | 6.72 ± 0.28 | 0.020 | 1.68 ± 0.09 | 0.140 |
| 28–33 | 151 (49.4) | 5.77 ± 0.21 | 1.43 ± 0.07 | ||
| > 34 | 68 (22.2) | 5.69 ± 0.32 | 1.49 ± 0.10 | ||
| Prepregnancy BMI (kg/m2) | |||||
| < 18.5 | 44 (14.4) | 6.18 ± 0.40 | 0.519 | 1.55 ± 0.13 | 0.955 |
| 18.5–25 | 236 (77.1) | 6.05 ± 0.17 | 1.51 ± 0.05 | ||
| > 25 | 26 (8.5) | 5.56 ± 0.52 | 1.52 ± 0.17 | ||
| Parityc | |||||
| 0 | 161 (52.7) | 6.54 ± 0.20 | 0.001 | 1.80 ± 0.06 | < 0.001 |
| ≥ 1 | 144 (47.2) | 5.46 ± 0.21 | 1.20 ± 0.07 | ||
| Educational level (years) | |||||
| ≤ 12 | 138 (45.0) | 5.78 ± 0.22 | 0.195 | 1.50 ± 0.07 | 0.330 |
| ≥ 13 | 168 (54.9) | 6.22 ± 0.20 | 1.53 ± 0.06 | ||
| Annual household income (million yen)c | |||||
| < 5 | 210 (69.0) | 5.96 ± 0.18 | 0.567 | 1.54 ± 0.06 | 0.934 |
| > 5 | 94 (30.9) | 6.13 ± 0.27 | 1.47 ± 0.09 | ||
| Smoking during pregnancy | |||||
| Yes | 130 (42.4) | 5.41 ± 0.23 | < 0.001 | 1.45 ± 0.07 | 0.353 |
| No | 176 (57.5) | 6.48 ± 0.19 | 1.56 ± 0.06 | ||
| Alcohol consumed during pregnancy | |||||
| Yes | 97 (31.6) | 5.95 ± 0.27 | 0.868 | 1.45 ± 0.09 | 0.560 |
| No | 209 (68.3) | 6.06 ± 0.18 | 1.55 ± 0.06 | ||
| Caffeine intake during pregnancy (mg/day) | 144.3 ± 123 | ρ = –0.058 | 0.310 | ρ = –0.125 | 0.028 |
| Fish intake during pregnancy | |||||
| Inshore fish | |||||
| ≤ 1–2 times/month | 166 (54.2) | 6.00 ± 0.20 | 0.750 | 1.55 ± 0.06 | 0.996 |
| ≥ 1–2 times/week | 140 (45.7) | 6.05 ± 0.22 | 1.48 ± 0.07 | ||
| Deep-sea fish | |||||
| ≤ 1–2 times/month | 148 (48.3) | 5.91 ± 0.22 | 0.223 | 1.52 ± 0.07 | 0.958 |
| ≥ 1–2 times/week | 158 (51.6) | 6.14 ± 0.21 | 1.51 ± 0.07 | ||
| Blood sampling period | |||||
| 23–31 weeks during pregnancy | 137 (44.7) | 6.35 ± 0.22 | < 0.001 | 1.59 ± 0.07 | 0.079 |
| 32–34 weeks during pregnancy | 82 (26.7) | 6.51 ± 0.28 | 1.49 ± 0.09 | ||
| 35–41 weeks during pregnancy | 87 (28.4) | 5.05 ± 0.27 | 1.43 ± 0.09 | ||
| Type of delivery | |||||
| Vaginal | 255 (83.3) | 6.14 ± 0.16 | 0.109 | 1.52 ± 0.05 | 0.915 |
| Cesarean section | 51 (16.6) | 5.45 ± 0.37 | 1.47 ± 0.12 | ||
| Gestational age (days) | 276.7 ± 9.4 | ρ = 0.057 | 0.314 | ρ = 0.051 | 0.371 |
| Infant characteristics | |||||
| Sex | |||||
| Male | 141 (46.0) | 6.18 ± 0.22 | 0.409 | 1.59 ± 0.07 | 0.040 |
| Female | 165 (53.9) | 5.89 ± 0.20 | 1.45 ± 0.06 | ||
| Birth weight (g) | |||||
| Total | 3076.9 ± 377.4 | ρ = –0.067 | 0.238 | ρ = –0.117 | 0.039 |
| Male | 3093.6 ± 374.2 | ρ = 0.075 | 0.372 | ρ = –0.076 | 0.367 |
| Female | 3062.5 ± 380.6 | ρ = –0.185 | 0.017 | ρ = –0.148 | 0.056 |
| aSpearman’s correlation (ρ) and p-value for continuous variables. bp-Values for Mann–Whitney U-test or Kruskal–Wallis test. cMissing data: parity (n = 1), annual household income (n = 2). | |||||