Table 2.

Regression analyses of maternal cortisol in early (15 wk) gestation and child hippocampus and amygdala volumes

Group	Right amygdala	Left amygdala	Right hippocampus	Left hippocampus
Girls	1.06 ± 0.46	0.15 ± 0.48	0.47 ± 1.11	−0.34 ± 0.97
P value	0.02 (q = 0.025)	0.76	0.68	0.72
Boys	−0.12 ± 0.28	−0.24 ± 0.30	−1.13 ± 0.66	−1.18 ± 0.61
P value	0.66	0.41	0.09	0.06

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. Significant P values were adjusted for multiple testing and q-values are presented that represent the minimum false-discovery rate that is incurred when calling a test significant. The following regression model was applied. Child brain volume = β₀ + β₁ * maternal cortisol at 15 wk gestation + β₂ * sex + β₁₂ * (maternal cortisol at 15 wk gestation * 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. 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.