Using item response theory to optimize measurement of chronic stress in pregnancy.

OBJECTIVE: Utilize Rasch analysis to develop an optimized self-reported measure of stress in pregnancy and examine the association with patient demographics and biologic measures of stress. STUDY DESIGN: Measured self-reported stress in pregnant women using 12 existing scales. Collected blood for biologic measures of stress (Epstein Barr Virus [EBV], C-Reactive Protein [CRP], Corticotropin Reactive Hormone [pCRH], and Adenocorticotropin Hormone [ACTH]). Used multidimensional scaling and Rasch analysis to produce an item reduced self-report measure. RESULTS: Enrolled 112 women. Survey items reduced to two factors: perceived stressors and buffers of stress. Women with a domestic partner had lower perceived stress (p = 0.003). Caucasian women reported higher buffers of stress (p = 0.045), as did women with private insurance (p < 0.001), a planned pregnancy (p < 0.01), and a domestic partner (p < 0.001). Women with higher buffers of stress had lower levels of pCRH (adjusted p = 0.01). CONCLUSION: Item reduced, optimized measures of stress were associated with significant differences in patient demographics and biologic measures of stress.

Prenatal Stress and the Cortisol Awakening Response in African-American and Caucasian Women in the Third Trimester of Pregnancy.

Objectives Prior studies have shown significant racial disparities in psychosocial stressors for pregnant women. One physiological mechanism by which prenatal stress is expressed is via the stress-sensitive hormone cortisol, which itself differs by race. In this study, we examine differences in cortisol awakening response (CAR) for African-American and Caucasian pregnant women during late pregnancy, particularly whether racial disparities are evident after accounting for measures of psychosocial stress. Methods During their third trimester of pregnancy (32-40 weeks of gestation), we asked women to self-collect salivary samples at home over 2 days. We then measured salivary cortisol across the day for 30 pregnant women (18 Caucasian; 12 African-American) to examine the CAR by race and by multiple measures of self-reported psychosocial stress, including perceived discrimination. Results Although the women in our sample showed normative cortisol diurnal rhythms (high on waking, peak 30 min post-waking, lowest at bedtime), we found that African-American women had blunted (smaller) awakening responses compared to Caucasian women (p < 0.05). The CAR was significantly larger in Caucasian women compared to African-American women even after accounting for covariates in a multivariate equation. However, when we added measures of psychosocial stress to the multivariate equation, higher levels of stress were significantly associated with a smaller CAR (p < 0.05), and the association between maternal race and CAR was no longer significant. Conclusions Our results add to a growing body of evidence that racial differences in the activity of the hypothalamic-pituitary-adrenal axis are associated with psychosocial stress during pregnancy.

Biological markers of stress in pregnancy: associations with chronic placental inflammation at delivery.

OBJECTIVE: To estimate the association between biomarkers of chronic stress during pregnancy and chronic placental inflammation. STUDY DESIGN: African-American and Caucasian pregnant women were recruited between May 2008 and July 2009. Blood samples were collected between 14 and 226/7 weeks and between 28 and 326/7 weeks of gestation. Samples were analyzed for serum C-reactive protein (CRP), Epstein-Barr virus (EBV) antibody, corticotropin-releasing hormone (CRH), and adrenocorticotropic hormone (ACTH). Placentas were collected at delivery and evaluated for chronic inflammation. RESULTS: Placentas were available from 88 of the 112 women enrolled in the study. EBV antibody levels were significantly higher during both the second and third trimester in women whose placentas demonstrated chronic villitis. CRP values also were significantly higher during the third trimester when chronic villitis was present. No association between placental chronic inflammation and CRH or ACTH was found. CONCLUSION: Chronic placental inflammation is associated with elevated serum EBV antibody and CRP levels during pregnancy.

Novel object exploration in the C58/J mouse model of autistic-like behavior.

Mouse models of autistic like behaviors are a valuable tool to use when studying the causes, symptoms, and potential treatments for autism. The inbred C58/J strain is a strain of interest for this model and has previously been shown to possess face validity for some of the core traits of autism, including low social behavior and elevated motor stereotypies. Higher order repetitive behaviors have not been extensively studied in this strain, or in mice in general. In this study, we looked for evidence of higher-order repetitive behaviors in the C58/J strain using a novel object assay. This assay utilized a mouse's natural exploratory behavior among unfamiliar objects to identify potential sequencing patterns in motor activity. The motor stereotypies displayed by the C58/J strain during testing were consistent with past studies. The C58/J strain also displayed a high preference for a single object in the round arena assays and the females demonstrating elevated sequencing patterns in the round arena. Although the C58/J strain did not show pervasive evidence of higher-order repetitive behaviors across all measures, there was evidence of higher order repetitive behaviors in certain situations. This study further demonstrates the potential of the C58/J mouse strains as a model for lower-order and potentially, higher-order repetitive behaviors. This study also demonstrates that the shape of the novel object arena can change the behavior displayed by the test animals. Further studies utilizing the C58/J strain and further validation of the novel object assay are warranted.