Cardiovascular and Metabolic Risk in Women in the First Year Postpartum: Allostatic Load as a Function of Race, Ethnicity, and Poverty Status.

OBJECTIVE: Allostatic load (AL) represents multisystem physiological "wear-and-tear" reflecting emerging chronic disease risk. We assessed AL during the first year postpartum in a diverse community sample with known health disparities. STUDY DESIGN: The Eunice Kennedy Shriver National Institute for Child Health and Human Development Community Child Health Network enrolled 2,448 predominantly low-income African-American, Latina, and White women immediately after delivery of liveborn infants at ≥20 weeks' gestation, following them over time with interviews, clinical measures, and biomarkers. AL at 6 and 12 months postpartum was measured by body mass index, waist:hip ratio, blood pressure, pulse, hemoglobin A1c, high-sensitive C-reactive protein, total cholesterol and high-density lipoprotein, and diurnal cortisol slope. RESULTS: Adverse AL health-risk profiles were significantly more prevalent among African-American women compared with non-Hispanic Whites, with Latinas intermediate. Breastfeeding was protective, particularly for White women. Complications of pregnancy were associated with higher AL, and disparities persisted or worsened through the first year postpartum. CONCLUSION: Adverse AL profiles occurred in a substantial proportion of postpartum women, and disparities did not improve from birth to 1 year. Breastfeeding was protective for the mother.

Psychosocial and demographic predictors of postpartum physical activity.

Physical activity promotes better health outcomes across the lifespan, and provides physical and mental health benefits for women who have recently given birth. However, research has not adequately characterized physical activity levels or risk factors for inadequate physical activity during the postpartum period. The objective of the present study was to describe levels and correlates of physical activity at 6 months postpartum in mothers of diverse race/ethnicity (55% African American, 23% White, 22% Hispanic/Latina), with the majority living in or near poverty. We analyzed data collected by the five-site Community Child Health Network study. Women (n = 1581) were recruited shortly after the birth of a child. Multinomial logistic regression models tested associations of demographic factors and self-reported stress in several life domains with total physical activity levels at 6-9 months postpartum, including activities done at work, at home, for transportation, and leisure. Thirty-five percent of participants in this sample reported low levels of physical activity. African American race, Latina ethnicity, and living in a rural area were associated with low levels of physical activity, whereas working outside the home was associated with high physical activity. Contrary to hypotheses, chronic stress was not associated with physical activity with the exception of financial stress, which predicted greater likelihood of being highly physically active. These findings suggest that optimal postpartum care should integrate physical activity promotion, and that African American, Latina, and rural-dwelling women may benefit most from efforts to promote activity following birth.

Chronic Stress and C-Reactive Protein in Mothers During the First Postpartum Year.

OBJECTIVE: Elevated levels of C-reactive protein (CRP) are associated with increased risk of cardiovascular and metabolic disease. The current study tested associations between psychosocial stress and CRP in a large sample of women during the first postpartum year. METHODS: We analyzed data collected by the five-site Community Child Health Network study, which studied a predominately poor population. Participants (n = 1206 women; 54% African American, 23% white, 23% Hispanic/Latina) were recruited shortly after the birth of a child. Multiple linear regression analyses tested associations of psychosocial stress in several life domains (financial, neighborhood, family, coparenting, partner relationship, discrimination, and interpersonal violence) with log-transformed CRP concentrations at 6-month and 1-year postpartum. RESULTS: Forty-eight percent of participants showed evidence of elevated CRP (≥3 mg/L) at 6-month postpartum, and 46% had elevated CRP at 12-month postpartum. Chronic financial stress at 1-month postpartum predicted higher levels of CRP at 6- (b = .15, SE = .05, p = .006) and 12-month postpartum (b = .15, SE = .06, p = .007) adjusting for race/ethnicity, income, education, parity, health behaviors, and chronic health conditions, though associations became nonsignificant when adjusted for body mass index. CONCLUSIONS: In this low-income and ethnic/racially diverse sample of women, higher financial stress at 1-month postbirth predicted higher CRP. Study findings suggest that perceived financial stress stemming from socioeconomic disadvantage may be a particular deleterious form of stress affecting maternal biology during the year after the birth of a child.

Explaining racial and ethnic inequalities in postpartum allostatic load: Results from a multisite study of low to middle income woment.

BACKGROUND: Racial and ethnic inequalities in women's health are widely documented, but not for the postpartum period, and few studies examine whether neighborhood, psychosocial, and biological factors explain these gaps in women's health. METHODS: Using prospective longitudinal data collected from 1766 low to middle income women between 2008 and 2012 by the Community Child Health Network (CCHN), we tested the extent to which adjustment for neighborhood, economic, psychological, and medical conditions following a birth explained differences between African American, Latina, and White women in an indicator of physiological dysregulation allostatic load (AL), at one year postpartum as measured by 10 biomarkers: Body Mass Index, Waist Hip Ratio, systolic and diastolic blood pressure, high sensitivity C-reactive protein, Hemoglobin A1c, high-density lipoprotein and cholesterol ratio, and diurnal cortisol. RESULTS: Mean postpartum AL scores were 4.65 for African American, 4.57 for Latina and 3.86 for White women. Unadjusted regression estimates for high AL for African American women (with White as the reference) were 0.80 (SD = 0.11) and 0.53 (SD = 0.15) for Latina women. Adjustment for household poverty, neighborhood, stress, and resilience variables resulted in a reduction of 36% of the excess risk in high AL for African Americans versus Whites and 42% of the excess risk for Latinas compared to Whites. CONCLUSIONS: Racial and ethnic inequalities in AL were accounted for largely by household poverty with additional contributions by psychological, economic, neighbourhood and medical variables. There remained a significant inequality between African American, and Latina women as compared to Whites even after adjustment for this set of variables. Future research into health inequalities among women should include a fuller consideration of the social determinants of health including employment, housing and prepregnancy medical conditions.

Lifetime racism and blood pressure changes during pregnancy: implications for fetal growth.

OBJECTIVE: Research suggests that exposure to racism partially explains why African American women are 2 to 3 times more likely to deliver low birth weight and preterm infants. However, the physiological pathways by which racism exerts these effects are unclear. This study examined how lifetime exposure to racism, in combination with maternal blood pressure changes during pregnancy, was associated with fetal growth. METHODS: African American pregnant women (n = 39) reported exposure to childhood and adulthood racism in several life domains (e.g., at school, at work), which were experienced directly or indirectly, meaning vicariously experienced when someone close to them was treated unfairly. A research nurse measured maternal blood pressure at 18 to 20 and 30 to 32 weeks gestation. Standardized questionnaires and trained interviewers assessed maternal demographics. Neonatal length of gestation and birth weight data were collected from medical charts. RESULTS: Childhood racism interacted with diastolic blood pressure to predict birth weight. Specifically, women with two or more domains of indirect exposure to racism in childhood and increases in diastolic blood pressure between 18 and 32 weeks had lower gestational age adjusted birth weight than the other women. A similar pattern was found for direct exposure to racism in childhood. CONCLUSIONS: Increases in diastolic blood pressure between the second and third trimesters predicted lower birth weight, but only when racism exposure in childhood (direct or indirect) was relatively high. Understanding pregnant African American women's lifetime direct and indirect experiences with racism in combination with prenatal blood pressure may improve identification of highest risk subgroups within this population.

Communalism predicts prenatal affect, stress, and physiology better than ethnicity and socioeconomic status.

The authors examined the relevance of communalism, operationalized as a cultural orientation emphasizing interdependence, to maternal prenatal emotional health and physiology and distinguished its effects from those of ethnicity and childhood and adult socioeconomic status (SES). African American and European American women (N = 297) were recruited early in pregnancy and followed through 32 weeks gestation using interviews and medical chart review. Overall, African American women and women of lower socioeconomic backgrounds had higher levels of negative affect, stress, and blood pressure, but these ethnic and socioeconomic disparities were not observed among women higher in communalism. Hierarchical multivariate regression analyses showed that communalism was a more robust predictor of prenatal emotional health than ethnicity, childhood SES, and adult SES. Communalism also interacted with ethnicity and SES, resulting in lower blood pressure during pregnancy for African American women and women who experienced socioeconomic disadvantage over the life course. The effects of communalism on prenatal affect, stress, and physiology were not explained by depressive symptoms at study entry, perceived availability of social support, self-esteem, optimism, mastery, nor pregnancy-specific factors, including whether the pregnancy was planned, whether the pregnancy was desired after conception, or how frequently the woman felt happy to be pregnant. This suggests that a communal cultural orientation benefits maternal prenatal emotional health and physiology over and above its links to better understood personal and social resources in addition to economic resources. Implications of culture as a determinant of maternal prenatal health and well-being and an important lens for examining ethnic and socioeconomic inequalities in health are discussed.

Stress and blood pressure during pregnancy: racial differences and associations with birthweight.

OBJECTIVE: To extend findings that African American women report greater stress during pregnancy, have higher blood pressure (BP), and are twice as likely to have low birthweight infants relative to white women. This study examines a) racial differences in associations between stress and BP during pregnancy, and b) the combined effects of stress and BP on infant birthweight in a sample of 170 African American and white women. METHODS: A prospective, longitudinal study of pregnant women was conducted in which measures of BP, stress, and other relevant variables were collected. Multiple measures of systolic and diastolic BP were taken at each of three points during pregnancy (18-20, 24-26, and 30-32 weeks gestation). RESULTS: Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) were positively associated with stress in pregnant African American women and not in pregnant white women. In analyses of birthweight, there were no main effects of BP or stress. However, a significant interaction demonstrated that, when stress was high, DBP was negatively associated with birthweight and a combination of high stress and high DBP predicted the lowest birthweight in the sample. Furthermore, African American women were twice as likely as white women to have a combination of high stress and high DBP. CONCLUSIONS: Racial differences in relationships between stress and BP, and the interactive effect of stress and DBP on birthweight together suggest that a high stress-high BP profile may pose a risk for lower birthweight among African American women, in particular, and possibly for all pregnant women.

Ethnic differences in adrenocorticotropic hormone, cortisol and corticotropin-releasing hormone during pregnancy.

Significant ethnic disparities exist in reproductive outcomes. A potential contributing factor may be the functioning of the hypothalamic-pituitary-adrenal (HPA) axis and placenta during pregnancy. In the present study, levels of cortisol, ACTH and CRH were determined longitudinally from the plasma of 310 African American, Hispanic and non-Hispanic White women at 18-20, 24-26 and 30-32 weeks' gestation. During pregnancy, African American women exhibited lower levels of cortisol than non-Hispanic women and higher levels of ACTH than Hispanic women. The trajectory of CRH increase also differed by ethnicity, with African Americans exhibiting the lowest levels both early and late in pregnancy. Higher levels of cortisol at 18-20 weeks were associated with higher levels of CRH at 30-32 weeks among the African American and Hispanic women, but not among non-Hispanic women. Ethnic differences persisted when adjusting statistically for sociodemographic and biomedical factors. The findings are consistent with the possibility that ethnic disparities in adverse birth outcomes may be due, in part, to differences in HPA axis and placental function.