Maternal Socioeconomic Mobility and Preterm Delivery: A Latent Class Analysis.

Objective Growing evidence suggests that maternal socioeconomic mobility (SM) is associated with pregnancy outcomes. Our study investigated the association between maternal SM from childhood to adulthood and the risk of preterm delivery (PTD), and examined heterogeneity of associations by race/ethnicity. Methods In this study, 3019 pregnant women enrolled from 5 Michigan communities at 16-27 weeks' gestation (1998-2004) provided their parents' socioeconomic position (SEP) indicators (education, occupation, receipt of public assistance) and their own and child's father's SEP indicators (education, occupation, Medicaid status, and household income) at the time of enrollment. Latent class analysis was used to identify latent classes of childhood SEP indicators, adulthood SEP indicators, and SM from childhood to adulthood, respectively. A model-based approach to latent class analysis with distal outcome assessed relations between latent class and PTD, overall and within race/ethnicity groups. Results Three latent classes (low, middle, high) were identified for childhood SEP indicators and adulthood SEP indicators, respectively; while four latent classes (static low, upward, downward, and static high) best described SM. Women with upward SM had decreased odds of PTD (Odds ratio = 0.60, 95% confidence interval: 0.42, 0.87), compared to those with static low SEP. This SM advantage was true for all women and most pronounced in white/others women. Conclusions Maternal experiences of upward SM may be important considerations when assessing PTD risk. Our results support the argument that policies and programs aimed at improving women's SEP could lower PTD rates.

Historical neighborhood poverty trajectories and child sleep.

OBJECTIVES: To determine whether historical neighborhood poverty measures are associated with mothers' reports of their children's sleep duration and to compare results from historical neighborhood poverty measures to contemporaneous measures of neighborhood poverty. DESIGN: The Geographic Research on Wellbeing (GROW) study is a follow-up survey of mothers who gave birth between 2003 and 2007. GROW mothers assessed their own and their children's health and health behaviors 5-10 years later (2012-2013). SETTING: Urban Californian counties. PARTICIPANTS: GROW respondents. MEASUREMENTS: We categorized children's sleep as adequate or inadequate using clinical age-specific guidelines and based on mothers' reports of their child's sleep duration. We conducted a latent class analysis to identify historical poverty classes for all California census tracts using data from 1970 to 2005-2009, and we categorized current neighborhood poverty based on data from 2005 to 2009 only. We then assigned children to different neighborhood exposure classes based on their neighborhood of residence at birth and follow-up. RESULTS: Logistic models indicated that net of controls for demographics, child behavior and health characteristics, mother characteristics, and household socioeconomic status, children who grew up in historically low (OR: 0.64, 95% confidence interval=0.45-0.92) or historically moderate poverty classes (OR: 0.68, 95% confidence interval=0.48-0.98) had lower odds of inadequate sleep duration compared with children who grew up in historically high poverty. We show that the historical specification of neighborhood poverty remained significant despite controls, whereas contemporaneous measures of neighborhood poverty did not. CONCLUSIONS: Our findings indicate strong associations between historical neighborhood poverty and child sleep duration.

Life Course Adversity and Prior Miscarriage in a Pregnancy Cohort.

BACKGROUND: Prior studies indicate associations between preconception adversities and risk of miscarriage, but few have considered type (e.g., financial, substance use, abuse) or timing (e.g., childhood, adulthood) of adversities. We examined relationships between life course adversities in multiple domains and probability of miscarriage. METHODS: Data came from women with at least one previous pregnancy in the Pregnancy Outcomes and Community Health (1998-2004) study (n = 2,106). Life course adversities in domains of abuse/witnessing violence, loss of someone close, economic hardship, and substance abuse were assessed via questionnaire and categorized as occurring during childhood only, adulthood only, both childhood and adulthood, or neither. We also calculated a cumulative adversity score. We used logistic regression models to estimate associations between life course adversity measures and the probability of miscarriage, and examined effect modification by race/ethnicity and maternal education. All models were adjusted for maternal age, race/ethnicity, education, and marital status. RESULTS: The odds of miscarriage were higher among women experiencing legal adversities during both childhood and adulthood (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.3-2.8) compared with women not experiencing legal adversities, and higher among women experiencing substance use adversities in childhood only (OR, 1.4; 95% CI, 1.1-1.7) compared with women not experiencing substance use adversities. Each additional adversity was marginally significantly associated with a 10% increase in odds of preterm birth (OR, 1.1; 95% CI, 1.0-1.1). Among women with only one prior miscarriage, no adversity measures were associated with miscarriage. CONCLUSIONS: Exposure to adversity in certain domains and across the life course modestly increased the odds of miscarriage.

Breastfeeding and Risk of Metabolic Syndrome in Children and Adolescents: A Systematic Review.

BACKGROUND: The beneficial effect of breastfeeding on individual components of the metabolic syndrome in children and adolescents has been reported, but it is unknown if there is an association between being breastfed and metabolic syndrome as a whole. Research aim: This systematic review was performed to assess quality and strength of evidence for the association between being breastfed and the development of metabolic syndrome in children and adolescents. METHODS: Articles were obtained from searches using PubMed and Embase databases, as well as from secondary searches through reference lists. Study quality was assessed using a three-level quality rating system. RESULTS: Of 11 studies reviewed, 7 found a protective association between breastfeeding and metabolic syndrome and 4 found no association. There was no clear dose-response relationship between duration of breastfeeding and metabolic syndrome risk and insufficient evidence to demonstrate an added effect of being exclusively breastfed. The overall quality of the articles was moderate. In general, lower quality articles found no significant association, whereas higher quality articles found a significant association. CONCLUSION: Our review demonstrated a limited amount of high-quality research on the relationship between being breastfed and development of metabolic syndrome in children and adolescents. The evidence presented in this review suggests that being breastfed may be protective against metabolic syndrome, but further research with improvements in study design, such as improved measurement of breastfeeding and the use of prospectively collected data, will improve our understanding of this relationship.

Preterm delivery trends by maternal race/ethnicity in the United States, 2006-2012.

PURPOSE: To estimate changes in preterm delivery (PTD) in the United States from 2006 to 2012 by clinical circumstance, timing of delivery, and race/ethnicity. METHODS: We used vital statistics natality data on all singleton live births from the 18 U.S. states continuously using the 2003 birth certificate from 2006 to 2012. We estimated change in PTD overall and by clinical circumstance (spontaneous vs. medically indicated) and delivery timing among all women and by race/ethnicity, using descriptive and multivariable regression methods. RESULTS: Overall, indicated, and spontaneous PTD declined by 10.31%, 8.40%, and 11.52%, respectively. Late-preterm, early-term, and post-term deliveries decreased substantially (12.13%, 18.37%, and 32.20%, respectively), with simultaneous increase (13.57%) in full-term deliveries. Non-Hispanic white, non-Hispanic black, and Asian/Pacific Islander women experienced larger declines in PTD compared with Hispanic and American Indian/Alaska Native women. Non-Hispanic white women experienced larger declines in late and medically indicated PTD, while non-Hispanic black women experienced larger declines in early and moderate and spontaneous PTD. CONCLUSIONS: Overall, spontaneous, and indicated PTD declined from 2006 to 2012. Declines were lower than previously reported and differed substantially by race/ethnicity.

Economic Conditions During Pregnancy and Adverse Birth Outcomes Among Singleton Live Births in the United States, 1990-2013.

We know little about the relationship between the macroeconomy and birth outcomes, in part due to the methodological challenge of distinguishing effects of economic conditions on fetal health from effects of economic conditions on selection into live birth. We examined associations between state-level unemployment rates in the first 2 trimesters of pregnancy and adverse birth outcomes, using natality data on singleton live births in the United States during 1990-2013. We used fixed-effect logistic regression models and accounted for selection by adjusting for state-level unemployment before conception and maternal characteristics associated with both selection and birth outcomes. We also tested whether associations between macroeconomic conditions and birth outcomes differed during and after (compared with before) the Great Recession (2007-2009). Each 1-percentage-point increase in the first-trimester unemployment rate was associated with a 5% increase in odds of preterm birth, while second-trimester unemployment was associated with a 3% decrease in preterm birth odds. During the Great Recession, however, first-trimester unemployment was associated with a 16% increase in odds of preterm birth. These findings increase our understanding of the effects of the Great Recession on health and add to growing literature suggesting that macro-level social and economic factors contribute to perinatal health.

Long-term neighborhood poverty trajectories and obesity in a sample of california mothers.

Neighborhoods (and people) are not static, and are instead shaped by dynamic long-term processes of change (and mobility). Using the Geographic Research on Wellbeing survey, a population-based sample of 2339 Californian mothers, we characterize then investigate how long-term latent neighborhood poverty trajectories predict the likelihood of obesity, taking into account short-term individual residential mobility. We find that, net of individual and neighborhood-level controls, living in or moving to tracts that experienced long-term low poverty was associated with lower odds of being obese relative to living in tracts characterized by long-term high poverty.

Residential segregation, political representation, and preterm birth among U.S.- and foreign-born Black women in the U.S. 2008-2010.

Although racial residential segregation is associated with preterm birth (PTB) among non-Hispanic black (NHB) women in the U.S., prior work suggests that increased black political power arising from segregation may be protective for infant health. We examined associations between residential segregation, black political representation, and preterm birth (PTB) among U.S- and foreign-born NHB women in major U.S. cities using birth certificate data from 2008 to 2010 (n=861,450). Each 10-unit increase in segregation was associated with 3-6% increases in odds of PTB for both U.S.- and foreign-born NHB women. Black political representation was not associated with PTB and did not moderate the association between residential segregation and PTB.

Are the poverty histories of neighbourhoods associated with psychosocial well-being among a representative sample of California mothers? An observational study.

BACKGROUND: We examine the association between the poverty histories of neighbourhoods and three indicators of psychosocial well-being-depressive symptoms, sense of control and number of stressors-in an observational study of mothers of young children in California. We also consider if length of residence in a neighbourhood moderates the association between neighbourhood poverty history and psychosocial well-being. METHODS: Data come from the Geographic Research on Well-being (GROW) Study, a subsample of mothers who completed the population-based California Maternal and Infant Health Assessment in 2003-2007 and were reinterviewed in 2012-2013. Poverty histories of neighbourhoods were constructed using the Neighbourhood Change Database (1970-2000) and American Community Survey (2005-2009). The analytic sample included 2726 women from GROW residing in 1906 census tracts. RESULTS: Adjusting for individual socioeconomic and demographic characteristics, women living in neighbourhoods where poverty decreased over the 40-year period had lower odds of depressive symptoms and a greater sense of control than women living in long-term, low-poverty neighbourhoods. Women living in long-term high-poverty neighbourhoods or in neighbourhoods where poverty increased over the 40-year period reported lower sense of control than women living in long-term, low-poverty neighbourhoods and these effects were modified by length of time living in the neighbourhood. No significant effects of neighbourhood poverty histories were found for number of stressors. CONCLUSIONS: Policies aimed at reducing neighbourhood poverty may improve mothers' psychosocial well-being.

Theoretical Insights into Preconception Social Conditions and Perinatal Health: The Role of Place and Social Relationships.

Recent efforts to explain the stark social and racial disparities in adverse birth outcomes that have persisted for decades in the U.S. have looked beyond prenatal factors, to explore preconception social conditions that may influence perinatal health via dysregulation of physiologic processes. The extant evidence supporting this link however remains limited, both due to a lack of data and theory. To address the latter, this manuscript generates a structured set of theoretical insights that further develop the link between two preconception social conditions - place and social relationships - and perinatal health. The insights propose the following. PLACE: necessarily encompasses all social contexts to which females are exposed from infancy through young adulthood; encompasses a variety of related exposures that, when possible, should be jointly considered; and may compound the effect of poverty-in childhood, adolescence, or young adulthood-on perinatal health. Social relationships: span relationships from early life through adulthood, and extend to intergenerational associations; often involve (or induce) major changes in the lives of individuals and should be examined with an emphasis on the developmental stage in which the change occurred; and necessarily encompass a lack of social integration, or, social isolation. We also identify potential biological and social-structural mechanisms linking these preconception social conditions to perinatal health, and conclude by identifying promising directions for future research.

Getting Under the Skin: Children's Health Disparities as Embodiment of Social Class.

Social class gradients in children's health and development are ubiquitous across time and geography. The authors develop a conceptual framework relating three actions of class-material allocation, salient group identity, and inter-group conflict-to the reproduction of class-based disparities in child health. A core proposition is that the actions of class stratification create variation in children's mesosystems and microsystems in distinct locations in the ecology of everyday life. Variation in mesosystems (e.g., health care, neighborhoods) and microsystems (e.g., family structure, housing) become manifest in a wide variety of specific experiences and environments that produce the behavioral and biological antecedents to health and disease among children. The framework is explored via a review of theoretical and empirical contributions from multiple disciplines and high-priority areas for future research are highlighted.

Stressors Across the Life-Course and Preterm Delivery: Evidence From a Pregnancy Cohort.

Objectives Growing evidence suggests that pre-conception stressors are associated with increased risk of preterm delivery (PTD). Our study assesses stressors in multiple domains at multiple points in the life course (i.e., childhood, adulthood, within 6 months of pregnancy) and their relation to PTD. We also examine heterogeneity of associations by race/ethnicity, PTD timing, and PTD clinical circumstance. Methods We assessed stressors retrospectively via mid-pregnancy questionnaires in the Pregnancy Outcomes and Community Health Study (1998-2004), a Michigan pregnancy cohort (n = 2559). Stressor domains included abuse/witnessing violence (hereafter "abuse"), loss, economic stress, and substance use. We used logistic and multinomial regression for the following outcomes: PTD (<37 weeks' gestation), PTD by timing (≤34 weeks, 35-36 weeks) and PTD by clinical circumstance (medically indicated, spontaneous). Covariates included race/ethnicity, education, parity, and marital status. Results Stressors in the previous 6 months were not associated with PTD. Experiencing abuse during both childhood and adulthood increased adjusted odds of PTD among women of white or other race/ethnicity only (aOR 1.6, 95 % CI 1.1, 2.5). Among all women, abuse in childhood increased odds of late PTD (aOR 1.5, 95 % CI 1.0, 2.2) while abuse in both childhood and adulthood non-significantly increased odds of early PTD (aOR 1.6, 95 % CI 0.9, 2.7). Sexual, but not physical, abuse in both childhood and adulthood increased odds of PTD (aOR 1.9, 95 % CI 1.0, 3.5). Conclusions Experiences of abuse-particularly sexual abuse-across the life-course may be important considerations when assessing PTD risk. Our results motivate future studies of pathways linking abuse and PTD.

Perceived and Objectively-Measured Neighborhood Violence and Adolescent Psychological Distress.

Prior research examining links between neighborhood violence and mental health has not been able to establish whether it is perceived levels of neighborhood violence, or actual levels of violent crime, that matter most for adolescents' psychological well-being. In this study, we ascertained both perceived neighborhood safety and objectively-measured neighborhood-level violent crime (using a novel geospatial index of police-reported crime incidents) for 4464 adolescent respondents from the California Health Interview Survey (CHIS 2011-2014). We used propensity score-matched regression models to examine associations between these measures and CHIS adolescents' symptoms of psychological distress. We found that adolescents who perceived their neighborhood to be unsafe were two times more likely than those who perceived their neighborhood to be safe to report serious psychological distress (OR = 2.4, 95 % CI = 1.20, 4.96). Adolescents who lived in areas objectively characterized by high levels of violent crime, however, were no more likely than their peers in safer areas to be distressed (OR = 1.41; 95 % CI = 0.60, 3.32). Our results suggest that, at the population level, adolescents' perceptions of neighborhood violence, rather than objective levels of neighborhood crime, are most salient for their mental health.

Health Impacts of the Great Recession: A Critical Review.

The severity, sudden onset, and multipronged nature of the Great Recession (2007-2009) provided a unique opportunity to examine the health impacts of macroeconomic downturn. We comprehensively review empirical literature examining the relationship between the Recession and mental and physical health outcomes in developed nations. Overall, studies reported detrimental impacts of the Recession on health, particularly mental health. Macro- and individual-level employment- and housing-related sequelae of the Recession were associated with declining fertility and self-rated health, and increasing morbidity, psychological distress, and suicide, although traffic fatalities and population-level alcohol consumption declined. Health impacts were stronger among men and racial/ethnic minorities. Importantly, strong social safety nets in some European countries appear to have buffered those populations from negative health effects. This literature, however, still faces multiple methodological challenges, and more time may be needed to observe the Recession's full health impact. We conclude with suggestions for future work in this field.

Post-partum Residential Mobility Among a Statewide Representative Sample of California Women, 2003-2007.

OBJECTIVES: Researchers often examine neighborhood socioeconomic environment and health during the perinatal period using geocoded addresses recorded on birth certificates at the time of delivery. Our objective was to assess the potential for post-partum neighborhood misclassification by examining whether women move neighborhoods during the immediate post-partum period, whether they move to neighborhoods of different socioeconomic status (SES), and whether mobility differs by maternal characteristics. METHODS: We used data from the 2003-2007 California Maternal and Infant Health Assessment (MIHA), an annual, statewide-representative survey of post-partum women, to examine women's neighborhood mobility patterns between giving birth and completing a survey 2-7 months post-partum. We examined whether women changed neighborhoods, whether moves were to neighborhoods of higher, lower, or similar socioeconomic status (SES), and whether these patterns differed by maternal race/ethnicity, maternal SES, or other demographic characteristics. RESULTS: Overall, 93% of women either did not move neighborhoods or moved to a neighborhood of similar SES post-partum. Only 4% of women moved to a neighborhood of lower SES and 3% to an area of higher SES. Mothers who were non-Hispanic black or US-born Hispanic, young, unmarried, primiparous, or lower SES were slightly more likely to move overall and more likely to move to neighborhoods with different SES, compared to other women. CONCLUSIONS: These findings suggest that geocoded addresses from birth certificates can be used to estimate women's neighborhood SES during the early post-partum period with little misclassification, an especially relevant finding for researchers using post-partum surveys.

Timing of birth: Parsimony favors strategic over dysregulated parturition.

OBJECTIVES: The "dysregulated parturition" narrative posits that the human stress response includes a cascade of hormones that "dysregulates" and accelerates parturition but provides questionable utility as a guide to understand or prevent preterm birth. We offer and test a "strategic parturition" narrative that not only predicts the excess preterm births that dysregulated parturition predicts but also makes testable, sex-specific predictions of the effect of stressful environments on the timing of birth among term pregnancies. METHODS: We use interrupted time-series modeling of cohorts conceived over 101 months to test for lengthening of early term male gestations in stressed population. We use an event widely reported to have stressed Americans and to have increased the incidence of low birth weight and fetal death across the country-the terrorist attacks of September 2001. We tested the hypothesis that the odds of male infants conceived in December 2000 (i.e., at term in September 2001) being born early as opposed to full term fell below the value expected from those conceived in the 50 prior and 50 following months. RESULTS: We found that term male gestations exposed to the terrorist attacks exhibited 4% lower likelihood of early, as opposed to full or late, term birth. CONCLUSIONS: Strategic parturition explains observed data for which the dysregulated parturition narrative offers no prediction-the timing of birth among gestations stressed at term. Our narrative may help explain why findings from studies examining associations between population- and/or individual-level stressors and preterm birth are generally mixed.

Beyond the cross-sectional: neighborhood poverty histories and preterm birth.

OBJECTIVES: We examined associations between longitudinal neighborhood poverty trajectories and preterm birth (PTB). METHODS: Using data from the Neighborhood Change Database (1970-2000) and the American Community Survey (2005-2009), we categorized longitudinal trajectories of poverty for California neighborhoods (i.e., census tracts). Birth data included 23 291 singleton California births from the Maternal and Infant Health Assessment (2003-2009). We estimated associations (adjusted for individual-level covariates) between PTB and longitudinal poverty trajectories and compared these to associations using traditional, cross-sectional measures of poverty. RESULTS: Compared to neighborhoods with long-term low poverty, those with long-term high poverty and those that experienced increasing poverty early in the study period had 41% and 37% increased odds of PTB (95% confidence interval [CI] = 1.18, 1.69 and 1.09, 1.72, respectively). High (compared with low) cross-sectional neighborhood poverty was not associated with PTB (odds ratio = 1.08; 95% CI = 0.91, 1.28). CONCLUSIONS: Neighborhood poverty histories may contribute to an understanding of perinatal health and should be considered in future research.

Post-term birth as a response to environmental stress : The case of September 11, 2001.

BACKGROUND AND OBJECTIVES: Despite growing interest in the role of maternal psychosocial stress as a determinant of preterm birth, no existing work has examined the relation between maternal stress and post-term birth (≥42 weeks). We hypothesize that prolonging gestation past term may represent an adaptive strategy to a suboptimal environment. METHODOLOGY: We examined the relationship between exposure to the September 2001 terrorist attacks and odds of post-term birth in California. We calculated the expected odds of post-term birth among conception cohorts of singleton gestations in California between October 1996 and November 2005. We used time series analysis to test for higher than expected odds of post-term birth among the 10 cohorts exposed to the attacks of September 2001 (those conceived from December 2000 to September 2001). RESULTS: The observed odds of post-term delivery among gestations at 33-36 weeks in September 2001 were higher than statistically expected for all race/ethnic and sex groups. CONCLUSIONS AND IMPLICATIONS: Our finding that odds of post-term birth were higher than expected among pregnancies exposed to the September 2001 terrorist attacks in late gestation provides initial support for the hypothesis that exposure to a psychosocial stress during pregnancy may result in prolonged gestation.

The contribution of maternal birth cohort to term small for gestational age in the United States 1989-2010: an age, period, and cohort analysis.

BACKGROUND: After decades of steady increase, mean birthweight in the US declined throughout the 1990s and early 2000s, a trend not fully explained by changes in length of gestation, medical practice, demographics, or maternal behaviours. We hypothesised that secular changes in health or social factors across women's life courses may have contributed to this unexplained trend and examined maternal birth cohort as a proxy measure of life-course determinants of fetal growth in the US. METHODS: We used the age, period, and cohort (APC) intrinsic estimator (IE) approach to estimate the contribution of maternal birth cohort (independent of maternal age and period of birth) to small for gestational age (SGA), overall and among term births, in the US from 1989 to 2010. We conducted analyses separately among foreign- and US-born Hispanic, non-Hispanic black (NHB), and non-Hispanic white mothers. RESULTS: We found evidence of a U-shaped relationship between maternal birth cohort and SGA among NHB women only. After accounting for maternal age and period of birth, risk of SGA among NHB women born in 1950 was 21.1% and decreased to 15.9% in 1970. However, NHB women born after 1970 experienced increasing risk (19.6% by the 1986 birth cohort). CONCLUSIONS: Our findings suggest that NHB women born after 1970 have experienced increasing risk of SGA. Declining risk of SGA across NHB maternal birth cohorts from 1950 to 1970, however, suggests the potential to reverse this trend. Results illustrate the need for research on health and social risk factors for SGA across the pre-pregnancy life course.