Birth In African American Women Research Articles

Preterm Birth in African American Women: A Multi-Omic Pilot Study in Early Pregnancy.

Preterm birth (PTB; <37weeks completed gestation) is a devastating problem affecting over 13 million live births worldwide. In the U.S., African Americans experience significantly higher rates of PTB compared to non-Hispanic Whites. PTB disparities have been linked to social determinants of health (e.g., socioeconomic status, discrimination). However, the biological underpinnings related to these associations are unclear. DNA methylation (DNAm) is subject to environmental influences, and DNAm modifications are known to affect gene expression. Using a multi-omic approach, we examined differences in combined DNA methylation (DNAm) and messenger RNA (mRNA) transcriptomic data from 20 pregnant African American women (12 PTB; 8 term birth) early in pregnancy (8-18weeks gestation). We found that the HLA-DQB2 gene was both differentially methylated (cg12296550; p = .02) and differentially expressed (p = .014; log2FC = 2.5) between women with PTB and term birth. Gene expression analysis showed HLA-DQB2 and HLA-DRB4 (p = .028; log2FC = -3.6) were the two most highly expressed genes. HLA-DQB2 expressed higher in PTB and HLA-DRB4 expressed higher in term birth. However, no genes remained significant (p < .05) after Bonferroni correction. HLA-DRB4 and AKR1C1 were identified as a potential biomarkers in dimensionality reduction models and are also important to immune function and allogenic breakdown. Altered gene expression may lead to inflammatory imbalances or allogenic intolerance resulting in PTB. This study provides proof-of-concept evidence for the feasibility and importance of future multi-omics studies with larger populations to further explore the genes and pathways identified here.

Maternal peripheral blood telomere length and preterm birth in African American women: a pilot study.

This study aimed to explore the association between preterm birth and telomere length of maternal peripheral blood in African American women. 78 African American women were recruited for this study between 2018 and 2023 from 2 prenatal clinics in central and east Texas. Participants provided blood samples and completed clinic questionnaires, with clinical data collected from their post-delivery medical records. Telomere length was measured using monochrome multiplex quantitative real-time polymerase chain reaction. Linear regression and multinomial logistic regression were used to analyze the association between telomere length and gestational length. Kruskal-Wallis's test and Fisher's exact test were used to compare preterm birth, early-term birth and full-term birth by telomere length, social-demographic characteristics, stress and discrimination. The rates of preterm birth was higher in pregnant women with shorter telomeres. After adjusting for confounders, for every 10-units increase in the relative telomere-to-single-copy gene (T/S) ratio, gestational days increased by 1.090 days (90% CI 0.182, 1.997), and for every 10-units decrease in the T/S ratio, the odds of preterm birth was 2.664 (90% CI 1.064, 6.673) times greater than the odds of full-term birth. No statistically significant associations were observed between stress, discrimination, and either preterm birth or telomere length. Maternal peripheral blood telomere shortening is associated with preterm birth, providing support to further explore the clinical utility of maternal telomere testing for prediction and early intervention of preterm birth and the study of biological mechanisms of spontaneous preterm birth.

DNA methylation changes in African American women with a history of preterm birth from the InterGEN study

BackgroundPreterm birth (< 37 weeks’ gestation) is a common outcome of pregnancy that has been associated with increased risk of cardiovascular disease for women later in life. Little is known about the physiologic mechanisms underlying this risk. To date, no studies have evaluated if differences in DNA methylation (DNAm) among women who experience preterm birth are short-term or if they persist and are associated with subsequent cardiovascular sequelae or other health disorders. The purpose of this study was to examine long-term epigenetic effects of preterm birth in African American mothers (n = 182) from the InterGEN Study (2014–2019). In this study, we determine if differences in DNAm exist between women who reported a preterm birth in the last 3–5 years compared to those who had full-term births by using two different approaches: epigenome-wide association study (EWAS) and genome-wide co-methylation analyses.ResultsThough no significant CpG sites were identified using the EWAS approach, we did identify significant modules of co-methylation associated with preterm birth. Co-methylation analyses showed correlations with preterm birth in gene ontology and KEGG pathways. Functional annotation analysis revealed enrichment for pathways related to central nervous system and sensory perception. No association was observed between DNAm age and preterm birth, though larger samples are needed to confirm this further.ConclusionsWe identified differentially methylated gene networks associated with preterm birth in African American women 3–5 years after birth, including pathways related to neurogenesis and sensory processing. More research is needed to understand better these associations and replicate them in an independent cohort. Further study should be done in this area to elucidate mechanisms linking preterm birth and later epigenomic changes that may contribute to the development of health disorders and maternal mood and well-being.

Methodologic Considerations for Epigenomic Investigation of Preterm Birth in African American Women.

Epigenetic modifications are chemical changes that can modify gene expression without changing the sequence of the gene. These modifications are potentially identifiable and reversible, making the epigenome an important area of research for discovering biomarkers to identify those who may be at risk and providing therapeutic interventions to prevent adverse health outcomes. African Americans bear a disproportionate risk of adverse health outcomes (e.g., hypertension, cancer). Indeed, African American women experience preterm birth (PTB; <37 completed weeks gestation) at more than twice the rate of non-Hispanic White women. Research suggests that environmental influences may play a significant role in PTB outcomes for this population. However, the biological pathways by which these influences contribute to PTB are poorly understood. This paper describes research methods and ethical considerations for the collection and analysis of biological samples based on our study examining the epigenetic regulation of stress pathways in PTB in pregnant African American women.

Complement Activation During Early Pregnancy and Clinical Predictors of Preterm Birth in African American Women.

Complement activation is essential for select physiologic processes during pregnancy; however, excess activation has been associated with an increased risk for preterm birth (PTB). African American (AA) women experience disproportionately higher rates of inflammation-associated PTB than other groups of women; thus, the purpose of this study was to explore the relationship between complement activation and perinatal outcomes among AA women. A plasma sample was collected between 8 and 14 weeks' gestation from a cohort of healthy AA women (N = 144) enrolled in a larger PTB cohort study. Medical record review was conducted to collect information on clinical factors (cervical length, health behaviors, gestational age at delivery). Multiple regression analysis was used to explore the relationships between complement marker (C3a/Bb) concentrations and the outcomes of interest after adjusting for baseline characteristics. C3a/Bb concentrations were not significant predictors of the gestational age at delivery, cervical length, or behavioral risk factors for PTB in this sample. Complement markers may not influence pregnancy outcomes among AA women in the same way as in predominantly white populations; however, more studies are needed to define complement dysregulation and the relationship with outcomes among AA women.

Early-life neighborhood context, perceived stress, and preterm birth in African American Women.

Stressors from multiple sources, across the life-course, may have independent and joint associations with preterm birth (PTB) risk in African American women. Using data from the Life-course Influences on Fetal Environments Study (LIFE; 2009–2011) of post-partum African American women from Metropolitan Detroit, Michigan (n=1365), we examined the association between perceived stress and PTB, and effect modification by perceptions of early-life neighborhood social control and disorder. We defined PTB as birth before 37 completed weeks of gestation. We used Cohen’s Perceived Stress scale, and valid and reliable scales of early-life (age 10) neighborhood social control and social disorder to quantify exposures. We estimated prevalence ratios (PR) and 95% confidence intervals (CI) with log binomial regression models- with separate interaction terms for perceived stress and each early-life neighborhood scale. We considered p < 0.10 significant for interaction terms. PTB occurred in 16.4% (n=224) of the study participants. In the total sample, perceived stress was not associated with PTB rates. However, there was suggestive evidence of a joint association between perceived stress and early-life neighborhood social disorder (p for interaction = 0.06), such that among women who reported high early-life neighborhood social disorder (n=660), perceived stress was positively associated with PTB (adjusted PR: 1.31; 95% CI: 1.05, 1.63). There was no association between perceived stress and PTB for women in the low early-life neighborhood social disorder strata (n=651) (adjusted PR: 0.95, 95% CI: 0.75, 1.21). There was no evidence that early-life neighborhood social control modified the association between perceived stress and PTB. Our results suggest that early-life neighborhood stressors may magnify the association between current perceived stress and PTB rates, in African American women. More research to confirm and explicate the biologic and/or psychosocial mechanisms of the reported association is warranted.

The Impact of Symptoms of Depression and Walking on Gestational Age at Birth in African American Women

BackgroundSymptoms of depression have been related to lower gestational age and preterm birth (<37 completed weeks gestation). Leisure time physical activity may have protective effects on preterm birth; however, less has been published with regard to other domains of physical activity such as walking for a purpose (e.g., for transportation) or the pathways by which symptoms of depression impact gestational age at birth. MethodsThis was a secondary analysis of available data of African American women. Women were interviewed within 3 days after birth. We proposed a model in which walking for a purpose during pregnancy mediated the effects of symptoms of depression (measured by the 20-item Center for Epidemiologic Studies-Depression [CES-D] scale) on gestational age at birth in a sample of 1,382 African American women. ResultsUsing structural equation modeling, we found that the direct effect of CES-D scores of 23 or greater, which have been correlated with major depression diagnosis, on gestational age at birth was -4.23 (p < .001). These results indicate that symptoms of depression were associated with a decrease in gestational age at birth of 4.23 days. Walking for a purpose mediated the effect of CES-D scores of 23 or greater on gestational age at birth. ConclusionsCompared with African American women without symptoms of depression, African American women who had symptoms of depression walked less for a purpose during their pregnancy and delivered infants with lower gestational age at birth. If not medically contraindicated, clinicians should incorporate walking as part of prenatal care recommendations and reassure women about safety of walking during pregnancy.

346: High perceived stress is associated with spontaneous preterm birth in african american women

346: High perceived stress is associated with spontaneous preterm birth in african american women

A Systematic Review of DNA Methylation and Preterm Birth in African American Women.

The causes of many cases of preterm birth (PTB) remain enigmatic. Increased understanding of how epigenetic factors are associated with health outcomes has resulted in studies examining DNA methylation (DNAm) as a contributing factor to PTB. However, few studies on PTB and DNAm have included African American women, the group with the highest rate of PTB. The objective of this review was to systematically analyze the existing studies on DNAm and PTB among African American women. Studies ( N = 10) were limited by small sample size, cross-sectional study designs, inconsistent methodologies for epigenomic analysis, and evaluation of different tissue types across studies. African Americans comprised less than half of the sample in 50% of the studies reviewed. Despite these limitations, there is evidence for an association between DNAm patterns and PTB. Future research on DNAm patterns and PTB should use longitudinal study designs, repeated DNAm testing, and a clinically relevant definition of PTB and should include large samples of high-risk African American women to better understand the mechanisms for PTB in this population.

Genetic variation associated with preterm birth in African-American women

Preterm birth is considered a multifactorial condition; however, emerging evidence suggests that genetic variation among individuals may have an important role. Prior studies have suggested that single-nucleotide polymorphisms associated with genes related to the immune system, and particularly the maternal inflammatory response, may be associated with an increased risk of preterm delivery. The objective of the study was to identify single-nucleotide polymorphisms associated with spontaneous preterm birth <37 weeks within a cohort of African-American women. This is a secondary analysis of a randomized trial that evaluated periodontal disease and preterm birth. Women were enrolled between 6 and 20 weeks' gestation at 3 prenatal care clinics between 2004 and 2007. Maternal DNA samples were collected and analyzed using a custom 1536 single-nucleotide polymorphismgenotyping array designed to assess genes involved in inflammation. Women were included in this study if they self-identified as African American. We excluded women with a multiple gestation or an indicated preterm delivery. We performed allele- and genotype-based analyses to evaluate the association between spontaneous preterm birth and tag single-nucleotide polymorphisms. We used a logistic regression to adjust for prior preterm birth in our genotype-based analysis. In a subgroup analysis, we compared women who delivered at <34 weeks' gestation to women who delivered at term. Within the microarray, we identified ancestry informative markers and compared global ancestry estimates among women who delivered preterm with those who delivered at term. Of the 833 African-American women in the study with genotype data, 77 women (9.2%) had a spontaneous preterm birth, whereas 756 women delivered at term. In an allele-based analysis, 4 single-nucleotide polymorphisms related to the genes for protein kinase C-α (PRKCA) were associated with increased risk of spontaneous preterm birth <37 weeks, whereas a single single-nucleotide polymorphism related to fms-related tyrosine kinase 1 (FLT1) was associated with spontaneous preterm birth <34 weeks. A genotype-based analysis revealed similar associations between single-nucleotide polymorphisms related to the PRKCA genes and spontaneous premature delivery. Additionally, single-nucleotide polymorphisms related to matrix metalloproteinase-2 (MMP2), tissue inhibitor of matrix metalloproteinase-2 (TIMP2), and interleukin 16 (IL16) genes were associated with spontaneous preterm birth <37 weeks in genotype-based analysis. Genetic variants related to MMP2, matrix metalloproteinase-1 (MMP1), and leukemia inhibitory factor receptor antisense RNA 1 (LIFR-AS1) genes were associated with higher rates of preterm birth <34 weeks. Ancestry estimates were similar between the women who had a spontaneous preterm birth and those who delivered at term. We identified tag single-nucleotide polymorphisms related to 7 genes that are critical to inflammation, extracellular remodeling, and cell signaling that were associated with spontaneous preterm birth in African-American women. Specifically, we found a strong association with the PRKCA gene. Genetic variation in these regions of the genome may be important in the pathogenesis of preterm birth. Our results should be considered in the design of future genomic studies in prematurity.

Relationships among psychosocial factors, biomarkers, preeclampsia, and preterm birth in African American women: A pilot

AimTo explore the relationships among psychosocial factors (optimism, uncertainty, social support, coping, psychological distress), biomarkers (cortisol, cytokines), preeclampsia, and preterm birth in African American women. MethodsForty-nine pregnant African American women completed psychosocial questionnaires and had blood collected for biomarkers between 26 and 36 weeks of gestation. Birth outcomes were obtained from birth records. ResultsWomen reporting higher levels of social support had lower levels of pro-inflammatory cytokines (IL-2, IL-5, and IL-6). Surprisingly, compared with low-risk pregnant women, women diagnosed with preeclampsia reported more optimism and less avoidance, and had lower levels of cortisol and IFN-γ. Similarly, compared to women with full-term birth, women with preterm birth reported higher levels of optimism and lower levels of avoidance, and had lower levels of IL-10. ConclusionPsychosocial factors influence inflammation and pregnancy outcomes. Close assessment and monitoring of psychosocial factors may contribute to improved pregnancy outcomes.

Stress, Inflammation and Preterm Birth in African American Women

In 2011, 11.7% of babies in the U.S. were born prematurely. African American women have higher rates of preterm birth compared with non-Hispanic white women. Chronic stressors experienced by African American women, such as living in disadvantaged neighborhoods and experiencing racial discrimination, have been related to higher rates of preterm birth. One potential pathway by which neighborhood disadvantage and racial discrimination can affect preterm birth is by increasing cumulative stress burden for these women. Psychological stress has been linked to preterm birth. The effects of chronic stress on preterm birth may occur through alterations of immune functions, thereby predisposing women to infection/inflammation. This review focuses on stress and inflammation as potential mechanisms for disparities in preterm birth in African American women. Prior research provides some evidence that stress-related immune interactions may contribute to preterm birth. Nurses need to be aware that African American women may experience chronic stressors in addition to the acute stress of having a premature infant.

Direct and Proxy Recall of Childhood Socio‐Economic Position and Health

The utility of proxy reporting within the life course framework has not been adequately assessed; therefore we sought to assess the magnitude and type of agreement that exists between index and proxy reports for bodyweight, health, and socio-economic position (SEP) in childhood. Participants were enrolled as part of an ongoing study of preterm birth in African American women in Metro Detroit. Post-partum women and their mothers (n = 333 pairs) provided retrospective reports about the woman's childhood bodyweight, health, and SEP. Agreement was assessed using kappa, weighted kappa (κ), and intraclass correlation coefficients (ICC). Log-linear models were used to describe the pattern of agreement for ordinal data. Birthweight and weight at age 18 was reported with a high level of agreement (ICC = 0.86 and 0.71, respectively). Kappa indicated moderate agreement for early and late childhood/adolescent weight. Log-linear models suggested that there was diagonal agreement plus linear by linear association for early childhood weight and linear by linear association in late childhood/adolescence. Reports of childhood medical problems and hospitalisations had only moderate agreement. Agreement for SEP in both early (κ = 0.14) and late childhood/adolescence (κ = 0.20) was poor. Log-linear models suggest a linear by linear association, indicating a positive association between the responses. Results suggest that proxy reports may be utilised in conjunction with an index report to provide an estimate of the accuracy of report or to more fully capture experiences over the life course. This may be particularly useful when multiple developmental periods are examined.

Relationships among Neighborhood Environment, Racial Discrimination, Psychological Distress, and Preterm Birth in African American Women

To (a) examine the relationships among objective and perceived indicators of neighborhood environment, racial discrimination, psychological distress, and gestational age at birth; (b) determine if neighborhood environment and racial discrimination predicted psychological distress; (c) determine if neighborhood environment, racial discrimination, and psychological distress predicted preterm birth; and (d) determine if psychological distress mediated the effects of neighborhood environment and racial discrimination on preterm birth. Descriptive correlational comparative. Postpartum unit of a medical center in Chicago. African American women (n(1) =33 with preterm birth; n(2) =39 with full-term birth). Women completed the instruments 24 to 72hours after birth. Objective measures of the neighborhood were derived using geographic information systems (GIS). Women who reported higher levels of perceived social and physical disorder and perceived crime also reported higher levels of psychological distress. Women who reported more experiences of racial discrimination also had higher levels of psychological distress. Objective social disorder and perceived crime predicted psychological distress. Objective physical disorder and psychological distress predicted preterm birth. Psychological distress mediated the effect of objective social disorder and perceived crime on preterm birth. Women's neighborhood environments and racial discrimination were related to psychological distress, and these factors may increase the risk for preterm birth.

Admixture Mapping to Identify Spontaneous Preterm Birth Susceptibility Loci in African Americans

Preterm birth is 1.5 times more common in African American (17.8%) than European American women (11.5%), even after controlling for confounding variables. We hypothesize that genetic factors may account for this disparity and can be identified by admixture mapping. This is a secondary analysis of women with at least one prior spontaneous preterm birth enrolled in a multicenter prospective study. DNA was extracted and whole-genome amplified from stored saliva samples. Self-identified African American patients were genotyped with a 1,509 single nucleotide polymorphism (SNP) commercially available admixture panel. A logarithm of odds locus-genome score of 1.5 or higher was considered suggestive and 2 or higher was considered significant for a disease locus. One hundred seventy-seven African American women with one or more prior spontaneous preterm births were studied. One thousand four hundred fifty SNPs were in Hardy-Weinberg equilibrium and passed quality filters. Individuals had a mean of 78.3% to 87.9% African American ancestry for each SNP. A locus on chromosome 7q21-22 was suggestive of an association with spontaneous preterm birth before 37 weeks of gestation (three SNPs with logarithm of odds scores 1.50-1.99). This signal strengthened when women with at least one preterm birth before 35.0 (eight SNPs with logarithm of odds scores greater than 1.50) and before 32.0 weeks of gestation were considered (15 SNPs with logarithm of odds scores greater than 1.50). No other areas of the genome had logarithm of odds scores higher than 1.5. Spontaneous preterm birth in African American women may be genetically mediated by a susceptibility locus on chromosome 7. This region contains multiple potential candidate genes, including collagen type 1-α-2 gene and genes involved with calcium regulation.

Cervicovaginal interleukin-6 as a predictor of preterm birth in African American women

BackgroundIdentification of women who will deliver preterm may reduce infant morbidity and mortality. In heterogeneous populations, fetal fibronectin (fFN) and interleukin-6 are excellent predictors of women who will not deliver within two weeks. African-Americans are at higher risk for preterm birth than Caucasians. This study compares the diagnostic utility of fFN and interleukin-6 in cervicovaginal fluid (CVF) to predict preterm birth within 14days of sampling in African-American and Caucasian women. MethodsInterleukin-6 was measured in 667 CVF samples from 580 women with and without symptoms of labor. The utility of CVF interleukin-6 and fFN to predict delivery was determined in the total population and in African-Americans and Caucasians separately. ResultsfFN positive (≥50μg/l) results were associated with delivery in ≤14days in African-Americans (Odds Ratios (OR) 8.7; Likelihood Ratio (LR) 3.7) (p<0.0001) and Caucasians (OR 11.9; LR 5.7) (p<0.01). A positive interleukin-6 (≥250ng/l) was associated with delivery in ≤14days in African-Americans (OR 12.7; LR 5.25) (p<0.0001), but not in Caucasians (OR 4.1; LR 3.2) (p=0.13). ConclusionsCVF interleukin-6 and fFN have similar diagnostic utilities in a diverse population. Interleukin-6 more accurately predicts delivery within 14days in African-Americans, while fFN is more accurate in Caucasians.

Prepregnancy body size, gestational weight gain, and risk of preterm birth in African-American women.

Studies of the association of prepregnancy body mass index (BMI) and preterm birth have been inconclusive, and no studies have examined the effect of central adiposity on risk. There is also uncertainty about optimal gestational weight gain among Black women. Using self-reported prospective data from the Black Women's Health Study, we investigated the relation of preterm birth to prepregnancy BMI (kg/m), waist circumference, and gestational weight gain among 7840 singletons born to black women, ages 21-44, during 1995-2003. We compared mothers of 1114 infants born 3 or more weeks early (597 spontaneous preterm births and 517 medically-indicated preterm births) with mothers of 6726 term infants. We used generalized estimating equation models to derive multivariable odds ratios (ORs) and 95% confidence intervals (CIs). Relative to normal weight women (BMI: 18.5-24.9), underweight women (BMI: <18.5) were at increased risk of both preterm birth subtypes; obese women (BMI > or = 30.0) were at increased risk of medically-indicated preterm birth and very early spontaneous preterm birth (<32 weeks' gestation). Waist circumference, a measure of central adiposity, was positively associated with medically-indicated preterm birth. Among obese women, average gestational weight gain in the second and third trimesters of <0.4 or >0.6 lbs/wk was associated with an increased risk of both preterm birth subtypes. Our data suggest that underweight increases risk of both preterm birth subtypes, while obesity increases risk of medically-indicated preterm birth and only a subgroup of spontaneous preterm births (<32 weeks' gestation). Central adiposity was an independent risk factor for medically-indicated preterm birth only. Among obese women, gestational weight gain within the range recommended by the 2009 Institute of Medicine report (0.4-0.6 lbs/week in the second and third trimesters) was associated with the lowest risk of preterm birth.

Acceptability of a self-sampling technique to collect vaginal smears for gram stain diagnosis of bacterial vaginosis

To diagnose asymptomatic bacterial vaginosis (BV), self-sampled vaginal smears were collected during a study of risk factors for preterm birth in African American women. More than 90% of those women who were willing to participate in the interview portion of the study were also willing to provide a self-sampled vaginal smear. The smears are an acceptable and efficient way of detecting BV in an urban minority population.

Acceptability of a self-sampling technique to collect vaginal smears for gram stain diagnosis of bacterial vaginosis

To diagnose asymptomatic bacterial vaginosis (BV), self-sampled vaginal smears were collected during a study of risk factors for preterm birth in African American women. More than 90% of those women who were willing to participate in the interview portion of the study were also willing to provide a self-sampled vaginal smear. The smears are an acceptable and efficient way of detecting BV in an urban minority population.