Figure 3. Association between maternal lifetime stress exposure and number of placental mitochondrial DNA mutations (homoplasmic + heteroplasmic = mutational load).
Model is adjusted for maternal age at birth (χ2= 2.61, p = 0.11), education (χ2= 0.01, p=0.92), and race/ethnicity (χ2= 27.78, p < 0.0001) based on augmented backward elimination algorithm. Results are similar for analyses using only heteroplasmic mutations (Table S7).