Pathways linking childhood abuse history and current socioeconomic status to inflammation during pregnancy

Abstract

Women who have experienced significant adversities during childhood and adulthood are at risk for excessive inflammation during pregnancy, but the mechanisms are unclear. Using structural equation modeling, we examined pathways from childhood abuse history and current socioeconomic status (SES) to inflammatory markers through indicators of health risk, recent stressors, and psychological distress in 214 women assessed at mid-pregnancy (5-31 weeks gestation). Self-reported data on socioeconomic indicators, childhood trauma history, pre-pregnancy body mass index (BMI), smoking, sleep quality, interpersonal conflict, recent life events, perceived stress, and depressive symptoms were collected, and serum levels of C-reactive protein (CRP) and interleukin (IL)-6 were determined. In separate models, pre-pregnancy BMI, sleep quality, and interpersonal conflict statistically explained the relationship between adversity and inflammation. These three intermediate variables were then entered into a multiple mediation analysis to examine unique effects. Childhood abuse history and current SES both demonstrated significant indirect effects on CRP through pre-pregnancy BMI, and current SES showed a significant indirect effect on IL-6 through all intermediate variables. When examining each indirect pathway individually, pre-pregnancy BMI and interpersonal conflict emerged as parallel pathways by which low current SES leads to elevated IL-6; the indirect pathway through sleep quality was no longer significant. Pre-pregnancy BMI and interpersonal conflict are two independent mechanisms by which adversity is associated with increased inflammation during pregnancy. Women who have been exposed to significant adversity may be at particular risk for obesity, sleep disruption, and interpersonal conflict, with implications for immune dysregulation during pregnancy.

Keywords: Body mass index (BMI); C-reactive protein (CRP); Childhood trauma; Interleukin-6 (IL-6); Interpersonal conflict; Obesity; Pregnant women; Sleep disruption; Socioeconomic status (SES); Stress.

Figure 1.

Measurement model. Note. Squared multiple correlations are shown above the observed indicator boxes. Error terms are not shown for visual clarity. SES = socioeconomic status. ^**p < .001.

Figure 2.

Standardized regression coefficients for Models 0 through 7. Note. Significant paths are shown in black solid lines, and nonsignificant paths are shown in gray dashed lines. The observed indicators for the two latent variables, error terms, and covariates (i.e., race, days gestation at sampling, maternal age, and pregnancy complications) are not shown for visual clarity. CRP = C-reactive protein. IL-6 = interleukin-6. SES = socioeconomic status. BMI = (pre-pregnancy) body mass index. PSQI = Pittsburgh Sleep Quality Index. TENSE = Test of Negative Social Exchange. PLES = Prenatal Life Events Scale. PSS = Perceived Stress Scale. CES-D = Center for Epidemiological Studies – Depression. *p < .05. **p < .01.

Figure 3.

Standardized regression coefficients for Model 8 (multiple mediation analysis). Note. Solid and dashed lines reflect significant and nonsignificant paths, respectively. The observed indicators for the two latent variables, error terms, and covariates (i.e., race, days gestation at sampling, maternal age, and pregnancy complications) are not shown for visual clarity. CRP = C-reactive protein. IL-6 = interleukin-6. SES = socioeconomic status. PSQI = Pittsburgh Sleep Quality Index. BMI = (pre-pregnancy) body mass index. TENSE = Test of Negative Social Exchange. *p < .05. ^**p < .01.