Table 3.

Explained variance in child amygdala and hippocampus volumes by maternal cortisol concentrations in mid and late gestation over and above variation explained by cortisol concentrations in early gestation

	Right amygdala	Left amygdala	Right hippocampus	Left hippocampus
Model 1: Maternal cortisol in midgestation (AUC1)
Girls	0.008 ± 0.04	0.02 ± 0.03	−0.03 ± 0.08	0.02 ± 0.07
P value	0.83	0.48	0.70	0.78
Boys	−0.009 ± 0.02	0 ± 0.02	0 ± 0.05	0.02 ± 0.05
P value	0.67	0.89	0.92	0.68
Model 2: Maternal cortisol in late gestation (AUC2)
Girls	0 ± 0.03	0 ± 0.03	0.01 ± 0.09	0.01 ± 0.09
P value	0.99	0.91	0.83	0.89
Boys	−0.014 ± 0.04	0 ± 0.04	−0.07 ± 0.13	−0.04 ± 0.12
P value	0.73	0.99	0.59	0.76

Values presented as β ± SEM. Sex-specific associations between maternal cortisol concentrations and child brain volumes were assessed by including an interaction term between maternal cortisol in pregnancy and sex of the child. All regression analyses were adjusted for obstetric risk, length of gestation, birth weight percentile, child age, sex, handedness, and maternal depression at child follow-up. The following regression model was applied. Child brain volume = β₀ + β₁ * maternal cortisol¹ + β₂ * sex + β₁₂ * (maternal cortisol¹ * sex) + β₃ * obstetric risk + β₄ * birth weight percentiles + β₅ * length of gestation + β₆ * maternal depression at child assessment + β₇ * child age at MRI assessment + β₈ * child handedness” + β₉ * maternal cortisol earlier in gestation². (¹AUC₁ in model 1 and AUC₂ in model 2; ²Maternal cortisol concentrations at 15 wk gestation in model 1 and AUC₁ in model 2.) Note that, by setting sex = 0 for girls, the estimate of β₁ provides the expected change in brain volume corresponding to one unit increase in maternal cortisol among girls. By setting sex = 1 for boys, the estimate of β₁ + β₁₂ provides the expected change in brain volume corresponding to one unit increase in maternal cortisol among boys.