Fig. 4

– Plot of individuals (A) and variables factor map (B) of the multiple factor analysis applied on the fetoplacental biometry and CP load profile at GD28. (A) on the plot of individuals, fetoplacental biometric profiles from the DE exposed group (n = 32) are represented by DE in red and fetoplacental biometric profiles from the clean-air exposed group (n = 32) are represented by C in black. The fetoplacental biometric profiles are significantly different between groups, namely between the two exposure groups (i.e., DE exposed and clean-air control) and can be significantly separated along dimension 1 (R² = 0.47, p < 0.01) and dimension 2 (R² = 0.38, p < 0.01). (B) All active variables are plotted into a variable factor map or correlation circle. The purple arrows consider individual organ DE particle loads, the dark blue arrows the placental and fetal weights and the light brown arrows the fetal weight-to-fetal organ weight ratios. The active variables involved in the construction of these dimensions are those whose vectors are the longest and closest to the circle. Abbreviations – CP: carbon particle; DE: diesel exhaust; GD: gestational day