Attenuation of maternal psychophysiological stress responses and the maternal cortisol awakening response over the course of human pregnancy

Figures & data

Table I.  Study characteristics for age, race/ethnicity, education, marital status, BMI and parity for pregnant group (PG, n = 148) and (CG, n = 36) subjects, as well as p-values for comparisons between the two groups.

	PG	CG	P
Age (years ± SD)	28.5 ± 6.0	32.0 ± 7.0	< 0.01
Race/ethnicity			n.s.
Non-Hispanic White	39%	36%
Hispanic White	30%	25%
Hispanic other	10%	11%
Non-Hispanic Black	5%	6%
Non-Hispanic Asian	7%	11%
Non-Hispanic other	9%	11%
Years of school completed	14.5 ± 2.5	14.0 ± 3.0	n.s.
Married	83%	78%	n.s.
BMI (pre-pregnancy BMI for pregnant group)	25.5 ± 6.1	25.9 ± 7.3	n.s.
Nulliparous	46%	51%	n.s.

n.s., non-significant.

Figure 1.  Mean HR ( ± SEM) and MAP ( ± SEM) values before, during, and after the TSST in pregnant women (n = 148) and in the CG (n = 36) for both study assessments. To graphically illustrate the findings of the three-level HLM models, percent increase ( ± SEM) from baseline is depicted for HR and MAP for both groups. Significant differences (p < 0.05) are indicated with an asterisk.

Table II.  Hierarchical linear model estimates for effects of time and gestational age at test predicting HR (a) and MAP (b) measurements.

	Parameter	SE	P
(a) HR (beats/min)
Intercept	78.97	0.838	< 0.001
Time	2.207	0.165	< 0.001
Time^2	− 0.1009	0.0075	< 0.001
Intercept × gestational age at test	0.5151	0.0617	< 0.001
Time × gestational age at test	− 0.0509	0.0097	< 0.001
Time^2 × gestational age at test	0.0021	0.0004	< 0.001
(b) MAP (mmHg)
Intercept	76.85	1.052	< 0.001
Time	2.299	0.188	< 0.001
Time^2	− 0.1020	0.0091	< 0.001
Intercept × gestational age at test	0.0764	0.0647	0.239
Time × gestational age at test	− 0.0431	0.0149	0.005
Time^2 × gestational age at test	0.0018	0.0007	0.012

Figure 2.  Mean distress levels ( ± SEM) before and after the TSST in pregnant women (n = 148) and in the CG (n = 36) for both study assessments. Significant differences (p < 0.05) are indicated with an asterisk.

Table III.  Explained session-by session variance (R²) for changes in HR, MAP, and distress from TSST 1 to 2 for the pregnant group (PG, n = 148) and the (CG, n = 36).

R^2 (for session-by-session variance)	PG	CG
HR	0.47	0.00
MAP	0.10	0.05
Distress	0.19	0.04

Figure 3.  Mean ( ± SEM) salivary cortisol concentrations in response to awakening (CAR) and over the course of the day in pregnant women (n = 148) and in the CG (n = 36) for both study assessments. To graphically illustrate the findings of the three-level HLM models, percent increase ( ± SEM) from awakening is depicted for both groups. Significant differences (p < 0.05) are indicated with an asterisk.

Table IV.  Hierarchical linear model estimates for effects of time (CAR and course of the day) and stage of gestation predicting salivary cortisol concentrations.

	Diurnal Cortisol [ln (nmol/L)+1]
	Parameter	SE	P
Intercept	2.901	0.047	< 0.001
Time (CAR)	0.9128	0.1359	< 0.001
Time^2 (CAR)	− 0.7087	0.1030	< 0.001
Time (course of day)	− 0.1319	0.0140	< 0.001
Time^2 (course of day)	0.0012	0.0010	0.219
Intercept × gestational age at test	0.0188	0.0041	< 0.001
Time (CAR) × gestational age at test	− 0.0321	0.0105	0.003
Time^2 (CAR) × gestational age at test	0.0250	0.0079	0.002
Time (day) × gestational age at test	0.0023	0.0012	0.074
Time^2 (day) × gestational age at test	− 0.0001	0.0001	0.605