Table 1. Cohort characteristics.
| Overall | Older cohort | Younger cohort | |||||
|---|---|---|---|---|---|---|---|
|
| |||||||
| Continuous variables | N | Median (IQR a) | N | Median (IQR a) | N | Median (IQR a) | p w |
| PFHxS (ng/mL) | 1092 | 1.45 (0.22; 5.15) | 605 | 4.49 (2.24; 8.43) | 487 | 0.20 (0.13; 0.31) | <0.001 |
| PFOS (ng/mL) | 1092 | 19.47 (8.67; 28.22) | 605 | 27.13 (23.18; 33.13) | 487 | 8.26 (6.22; 10.71) | <0.001 |
| PFOA (ng/mL) | 1092 | 2.40 (1.45; 3.59) | 605 | 3.34 (2.56; 4.01) | 487 | 1.40 (0.95; 1.95) | <0.001 |
| PFNA (ng/mL) | 1092 | 0.62 (0.48; 0.83) | 605 | 0.59 (0.46; 0.79) | 487 | 0.66 (0.52; 0.86) | <0.001 |
| PFDA (ng/mL) | 1092 | 0.28 (0.21; 0.37) | 605 | 0.28 (0.22; 0.38) | 487 | 0.26 (0.19; 0.35) | 0.006 |
| Total breastfeeding (months) | 1030 | 9 (6; 12) | 577 | 9 (6; 12) | 453 | 9.5 (6; 12) | 0.91 |
| Exclusive breastfeeding (months) | 1029 | 5 (4; 6) | 576 | 5 (4; 6) | 453 | 5 (4; 6) | 0.49 |
| Maternal age (years) | 1130 | 30.3 (26.2; 33.9) | 640 | 30.1 (25.9; 33.2) | 490 | 30.6 (26.7; 34.5) | 0.02 |
| Pre-pregnancy BMI (kg/m2) | 1129 | 23.2 (21.2; 25.9) | 640 | 23.0 (21.2; 25.6) | 489 | 23.7 (21.2; 26.0) | 0.06 |
| Birth weight (g) | 1130 | 3700 (3400; 4030) | 640 | 3725 (3400; 4000) | 490 | 3700 (3400; 4050) | 0.94 |
|
| |||||||
| Binary variables | N | n (%) | N | n (%) | N | n (%) | p c |
|
| |||||||
| Previous births | 1128 | 804 (71.3) | 640 | 464 (72.5) | 488 | 340 (69.7) | 0.30 |
| Pregnancy alcohol intake | 1127 | 288 (25.6) | 639 | 264 (41.3) | 488 | 24 (4.9) | <0.001 |
| Pregnancy smoking | 1128 | 254 (22.2) | 640 | 177 (27.7) | 488 | 77 (15.8) | <0.001 |
| Maternal education beyond primary school | 1124 | 872 (77.6) | 640 | 454 (70.9) | 484 | 418 (86.4) | <0.001 |
| Maternal employment | 1129 | 843 (74.7) | 640 | 451 (70.5) | 489 | 392 (80.2) | <0.001 |
| Caesarean section | 1127 | 128 (11.4) | 640 | 65 (10.2) | 487 | 63 (12.9) | 0.15 |
| Preterm delivery (GA < 37 weeks) | 1127 | 28 (2.5) | 640 | 13 (2.0) | 487 | 15 (3.1) | 0.26 |
a
IQR: Inter Quartile Range: 25; 75 percentile
w
p-value for difference between cohorts (Wilcoxon's rank-sum test)
c
p-value for difference between cohorts (Chi squared test)
GA Gestational Age