Ethnic identity as a moderator of associations between discrimination and physiological indices of stress reactivity

• In Event: Prenatal stress exposure among Black American women: Implications for maternal and child health outcomes

Abstract

Black American women living in low resource environments are exposed to multiple chronic and intermittent acute stressors that put them at greater risk for pregnancy complications and poor birth outcomes, relative to their counterparts. Stress exposure impacts multiple regulatory processes including hypothalamic pituitary adrenal (HPA) axis activity and autonomic nervous system (ANS) functioning. Alterations in these regulatory systems over time may be mechanisms through which maternal stress exposures impact pregnancy and birth outcomes. Moreover, there is evidence that stressors of different types vary in the magnitude of effects during the perinatal period. For instance, a previous study of Black American pregnant women that found that discrimination stress, but not overall perceived stress or poverty-related stress, was associated with blunted cortisol reactivity and higher overall heart rate. The current study builds upon this work by investigating the extent to which affiliation with one’s ethnic identity moderates the associations between discrimination stress and HPA-axis and ANS activity during laboratory stress tasks.

Seventy-two pregnant, Black American women, who are recipients of public assistance, were recruited to the Nutrition and Pregnancy Study (NAPS). Between 10 to 16 weeks of gestation, participants completed a laboratory assessment that included the Trier Social Stress Test (TSST). During laboratory visits, salivary cortisol was collected at 5 time points and heart rate variability (HRV) was continuously. Self-report measures included the Everyday Discrimination Scale (EDS) and the sense of belonging subscale of the Multigroup Ethnic Identity Measure (MEIM). Relationships among variables were examined a generalized linear models (GLM). As the sphericity assumption was not met, the Greenhouse-Geisser correction was used. Analyses controlled for participant age and time of data collection.

Sense of belonging to one’s ethnic group was modestly associated with cortisol levels across the visit (F [1.69, 11.44] = 2.60, p = .09). No other effects were observed. Regarding ANS functioning, there was a within-subjects effect of sense of belonging on within-subjects HRV over the course of the visit (F [3.96, 138.66] = 3.09, p < .05). Regarding between-subjects effects, participants reporting high levels of discrimination had higher HRV throughout the task (F [1, 35] = 8.27, p < .01). Sense of belonging was associated with somewhat lower HRV (F [1, 35] = 3.16, p = .08). There was an interaction effect between sense of belonging and experiences of discrimination (F [1, 35] = 8.27, p < .01) such that sense of belonging attenuated HRV among women with high levels of discrimination. Our findings point to the importance of examining cultural processes in the well-being of pregnant African-American women, as these processes may buffer the effects of discrimination stress on perinatal health and ultimately on offspring development.

Authors

• Kimberley Mbayiwa, University of Chicago
  Presenting Author

• Johnny Berona, University of Chicago
  Non-Presenting Author

• Rimma Ilyumzhinova, University of Chicago
  Non-Presenting Author

• Anna Wiktoria Sroka, University of Chicago
  Non-Presenting Author

• Katharine Ross, University of Chicago
  Non-Presenting Author

• Willa Meyer, University of Chicago
  Non-Presenting Author

• Alison E. Hipwell, University of Pittsburgh
  Non-Presenting Author

• Kate Keenan, University of Chicago
  Non-Presenting Author