Table 1 – Fetoplacental biometry at GD28. Female pregnant rabbits inhaled either 1 mg/m3 of diesel exhaust (DE) or clean air (C) for 2 h/day, 5 days/week from GD3 to 27. Dams were euthanised, and fetoplacental units of control (C) and exposed (DE) groups were collected at GD28. The effect of gestational exposure to diesel engine exhaust on the fetoplacental biometry was estimated by assessing the association between organ weight or weight ratio and carbon particle (CP) load in each fetal organ. Here we used linear mixed-effects models adjusted for treatment and fetal sex with random intercept effect of dam. All data are expressed as median (Q1; Q3) for the individual statistics (based on average values per fetus) and statistics per litter (based on average values per dam) to show between-fetus and between-dam variability, respectively. *p < 0.05 is considered statistically significant. Abbreviations – CP: carbon particle; DE: diesel exhaust; GD: gestational day
Variable | No. of fetuses | Statistics per fetus Median (Q1; Q3) | Statistics per litter Median (Q1; Q3) | Linear mixed model | ||
|---|---|---|---|---|---|---|
Estimate | 95%CI | p-value | ||||
Placental CP load | ||||||
Fetal weight (g) | 56 | 36 (32; 38) | 35 (31; 38) | -4.8 | -11; 2.2 | 0.17 |
Placental weight (g) | 56 | 7.4 (6.8; 8.4) | 8.4 (7.0; 8.8) | 0.49 | -0.97;1.94 | 0.50 |
Placental efficiency | 56 | 4.8 (4.1; 5.4) | 4.4 (3.5; 5.2) | -0.73 | -1.6; 0.13 | 0.10 |
Placenta/fetus weight ratio x 10 | 56 | 2.1 (1.9; 2.5) | 2.3 (1.9; 2.9) | 0.46 | -0.021; 0.95 | 0.067 |
Heart CP load | ||||||
Fetal weight (g) | 27 | 36 (32; 38) | 35 (29; 36) | -0.60 | -8.5; 7.3 | 0.87 |
Heart weight (g) | 27 | 0.20 (0.17; 0.24) | 0.20 (0.19; 0.23) | -0.023 | -0.087; 0.47 | 0.44 |
Heart/fetus weight ratio x 103 | 27 | 5.7 (5.1; 6.4) | 5.9 (5.4; 6.5) | -0.39 | -1.9; 0.46 | 0.67 |
Kidney CP load | ||||||
Fetal weight (g) | 27 | 34 (32; 39) | 35 (31; 36) | -3.2 | -13; 6.7 | 0.49 |
Kidney weight (g) | 27 | 0.17 (0.13; 0.18) | 0.15 (0.15; 0.17) | -0.033 | -0.11; 0.04 | 0.34 |
Kidney/fetus weight ratio x 103 | 27 | 4.5 (4.2; 5.0) | 4.4 (4.3; 4.7) | -0.47 | -1.5; 0.59 | 0.35 |
Liver CP load | ||||||
Fetal weight (g) | 26 | 34 (31; 38) | 34 (32; 39) | 0.25 | -12; 13 | 0.97 |
Liver weight (g) | 26 | 2.4 (1.9; 2.6) | 2.4 (1.9; 2.7) | 0.039 | -1.2; 1.3 | 0.95 |
Liver/fetus weight ratio x 102 | 26 | 6.8 (6.1; 7.4) | 6.8 (5.7; 7.3) | -0.011 | -1.6;1.6 | 0.99 |
Lung CP load | ||||||
Fetal weight (g) | 28 | 35 (31; 38) | 35 (32; 38) | 1.07 | -10;13 | 0.84 |
Lung weight (g) | 28 | 0.98 (0.87; 1.1) | 1.0 (0.87; 1.2) | 0.12 | -0.25; 0.48 | 0.49 |
Lung/fetus weight ratio x 102 | 28 | 2.8 (2.7; 3.0) | 2.8 (2.7; 3.0) | 0.33 | -0.36; 1.0 | 0.32 |
Gonad CP load | ||||||
Fetal weight (g) | 27 | 36 (32; 38) | 35 (29; 39) | 4.5 | -6.0; 15 | 0.37 |