Preterm Birth Risk and Maternal Nativity, Ethnicity, and Race.

Importance: Immigrant birthing people have lower rates of preterm birth compared with their US-born counterparts. This advantage and associated racial and ethnic disparities across the gestational age spectrum have not been examined nationally. Objective: To examine associations of maternal nativity, ethnicity, and race with preterm birth. Design, Setting, and Participants: This cohort study used birth certificates from the National Vital Statistics System to analyze in-hospital liveborn singleton births in the US between January 1, 2009, and December 31, 2018. Data were analyzed from January to June 2023. Exposure: Mutually exclusive nativity, ethnicity, and race subgroups were constructed using nativity (defined as US-born or non-US-born), ethnicity (defined as Hispanic or non-Hispanic), and race (defined as American Indian or Alaska Native, Asian, Black, Native Hawaiian or Other Pacific Islander, White, or other [individuals who selected other race or more than 1 race]). Main Outcomes and Measures: The primary outcome of interest was preterm birth. Modified Poisson and multinomial logistic regression models quantified relative risk (RR) of preterm birth overall (<37 weeks' gestation) and by gestational category (late preterm: 34-36 weeks' gestation; moderately preterm: 29-33 weeks' gestation; and extremely preterm: <29 weeks' gestation) for each maternal nativity, ethnicity, and race subgroup compared with the largest group, US-born non-Hispanic White (hereafter, White) birthing people. The RR of preterm birth overall and by category was also measured within each racial and ethnic group by nativity. Models were adjusted for maternal demographic and medical covariates, birth year, and birth state. Results: A total of 34 468 901 singleton live births of birthing people were analyzed, with a mean (SD) age at delivery of 28 (6) years. All nativity, ethnicity, and race subgroups had an increased adjusted risk of preterm birth compared with US-born White birthing people except for non-US-born White (adjusted RR, 0.85; 95% CI, 0.84-0.86) and Hispanic (adjusted RR, 0.98; 95% CI, 0.97-0.98) birthing people. All racially and ethnically minoritized groups had increased adjusted risks of extremely preterm birth compared with US-born White birthing people. Non-US-born individuals had a decreased risk of preterm birth within each subgroup except non-Hispanic Native Hawaiian or Other Pacific Islander individuals, in which immigrants had significantly increased risk of overall (adjusted RR, 1.07; 95% CI, 1.01-1.14), moderately (adjusted RR, 1.10; 95% CI, 0.92-1.30), and late (adjusted RR, 1.11; 95% CI, 1.02-1.22) preterm birth than their US-born counterparts. Conclusions and Relevance: Results of this cohort study suggest heterogeneity of preterm birth across maternal nativity, ethnicity, and race and gestational age categories. Understanding these patterns could aid the design of targeted preterm birth interventions and policies, especially for birthing people typically underrepresented in research.

Associations of salivary aldosterone levels during pregnancy with maternal blood pressure and birth weight-for-gestational age in a Mexico City birth cohort.

OBJECTIVE: To determine associations of maternal salivary aldosterone with blood pressure (BP) in pregnancy and infant birth weight-for-gestational age (BWGA). METHODS: We measured maternal salivary aldosterone, BP and BWGA z-scores in 471 Mexico City pregnancy cohort participants and performed multivariable linear regression of BP and BWGA on log-aldosterone levels. RESULTS: Log-aldosterone was positively associated with diastolic BP (ß = 0.12 95% CI: 0.04, 0.21). There were no main effects of log-aldosterone on BWGA. However, we detected an interaction between log-aldosterone and BP in association with BWGA; higher log-aldosterone was associated with lower BWGA in the lowest (ß = -0.12, 95% CI: -0.26, 0.02) and highest (ß = -0.12, 95% CI: -0.29, 0.06) BP tertiles. In contrast, in the middle BP tertile the association was positive (ß = 0.09, 95% CI: -0.02, 0.20), p for interaction = 0.03. CONCLUSION: Higher maternal salivary aldosterone is positively associated with diastolic BP and may affect fetal growth differently depending on concurrent maternal blood pressure.

The role of neighborhood deprivation in the cervicovaginal microbiota.

BACKGROUND: Lactobacillus-deficient cervicovaginal microbiota is associated with spontaneous preterm birth and is more common among Black individuals. Persistent racial segregation in the United States has led to differential neighborhood exposures by race that can affect pregnancy outcomes. The extent to which neighborhood exposures may explain racial differences in the cervicovaginal microbiota is unknown. OBJECTIVE: This study aimed to determine whether neighborhood deprivation, defined as material community deprivation, is associated with a Lactobacillus-deficient cervicovaginal microbiota in a prospective cohort of pregnant individuals. Our hypothesis was that racial differences in neighborhood deprivation may explain the higher prevalence of Lactobacillus-deficient cervicovaginal microbiota in Black birthing people. STUDY DESIGN: This study analyzed data from Motherhood and Microbiome, a prospective pregnancy cohort enrolled from prenatal clinics in a single hospital system 2013-2016 in which a Lactobacillus-deficient cervicovaginal microbiota was previously shown to be associated with spontaneous preterm birth. This study geocoded addresses to obtain census tract neighborhood deprivation data from the Brokamp Nationwide Community Deprivation Index that uses weighted proportions of poverty, income, public assistance, lack of health insurance, and vacant housing. Generalized linear mixed models quantified associations of deprivation with the cervicovaginal microbiota accounting for geographic clustering by census tract and potential confounders. Because of different distributions of neighborhood deprivation and the cervicovaginal microbiota, race-stratified models were used. Mediation analyses quantified the extent to which deprivation may contribute to racial differences in the cervicovaginal microbiota. RESULTS: Higher neighborhood deprivation was associated with a Lactobacillus-deficient cervicovaginal microbiota. Per standard deviation increment of deprivation, participants had 28% higher adjusted odds (adjusted odds ratio, 1.28; 95% confidence interval, 1.04-1.58) of a Lactobacillus-deficient microbiota. Black participants had higher odds of a Lactobacillus-deficient microbiota than White participants (adjusted odds ratio, 4.00; 95% confidence interval, 2.05-8.26), and mediation analysis revealed that deprivation accounted for 22% (P=.046) of that disparity. CONCLUSION: Neighborhood deprivation was associated with Lactobacillus-deficient cervicovaginal microbiota and may partially explain Black-White disparities in the cervicovaginal microbiota. Mechanistic studies to explore how environmental exposures modify the cervicovaginal microbiota are warranted to identify novel opportunities for future interventional strategies to prevent preterm birth. As the findings demonstrate a potential biological effect from neighborhood conditions, policies that drive urban planning should be explored to improve pregnancy outcomes.

Giving Birth With a Midwife in Attendance: Associations of Race and Insurance Status With Continuity of Midwifery Care in Philadelphia.

INTRODUCTION: From 2013 to 2019, Black women comprised 73% of pregnancy-related deaths in Philadelphia. There is currently a dearth of research on the continuity of midwifery care from initiation of prenatal care through birth in relation to characteristics such as race/ethnicity and income. The aim of this study was to investigate whether race/ethnicity and insurance status were associated with the likelihood of a pregnant person who begins prenatal care with a midwife to remain in midwifery care for birth attendance. METHODS: This was a retrospective cohort study of a diverse population of pregnant patients who gave birth in a large tertiary care hospital and had their first prenatal visit with a certified nurse-midwife (CNM) between June 2, 2009, and June 30, 2020 (n = 5121). We used multivariable, log-binomial regression models to calculate risk ratios of transferring to physician care (vs remaining within CNM care), adjusted for age, race/ethnicity, prepregnancy body mass index, insurance type, and comorbidities. RESULTS: After adjusting for pregnancy-related risk factors, non-Hispanic Black patients (adjusted relative risk [aRR], 1.14; 95% CI, 1.04-1.24) and publicly insured patients (aRR, 1.11; 95% CI, 1.01-1.22) were at higher risk of being transferred to physician care compared with non-Hispanic White and privately insured patients. Secondary analysis revealed that non-Hispanic Black patients had higher risk of transferring and having an operative birth (aRR, 1.35; 95% CI, 1.18-1.55), whereas publicly insured patients were at higher risk of being transferred for reasons other than operative births (aRR, 1.35; 95% CI, 1.18-1.54). DISCUSSION: These findings indicate that Black and publicly insured patients were more likely than White and privately insured patients to transfer to physician care even after adjustment for comorbid conditions. Thus, further research is needed to identify the factors that contribute to racial and economic disparity in continuity of midwifery care.

Observations of Positive Parenting from Online Parent-Child Interactions at Age 1.

Objective: Brief, reliable, and cost-effective methods to assess parenting are critical for advancing parenting research. Design: We adapted the Three Bags task and Parent Child Interaction Rating System (PCIRS) for rating online visits with 219 parent-child dyads (White, n = 104 [47.5%], Black, n = 115 [52.5%]) and combined the video data with survey data collected during pregnancy and when children were aged 1. Results: The PCIRS codes of positive regard, stimulation of child cognitive development, and sensitivity showed high reliability across the three parent-child interaction tasks. A latent positive parenting factor combining ratings across codes and tasks showed good model fit, which was similar regardless of parent self-identified race or ethnicity, age, socioeconomic disadvantage, marital/partnered status, and parity, as well as methodological factors relevant to the online video assessment method (e.g., phone vs. laptop/tablet). In support of construct validity, observed positive parenting was related to parent-reported positive parenting and child socioemotional development. Finally, parent reports of supportive relationships in pregnancy, but not neighborhood safety or pandemic worries, were prospectively related to higher positive parenting observed at age 1. With the exception of older parental age and married/partnered status, no other parent, child, sociodemographic, or methodological variables were related to higher overall video exclusions across tasks. Conclusions: PCIRS may provide a reliable approach to rate positive parenting at age 1, providing future avenues for developing more ecologically valid assessments and implementing interventions through online encounters that may be more acceptable, accessible, or preferred among parents of young children.

Spatial Patterning of Spontaneous and Medically Indicated Preterm Birth in Philadelphia.

Preterm birth (PTB) remains a key public health issue that disproportionately affects Black individuals. Since spontaneous PTB (sPTB) and medically indicated PTB (mPTB) may have different causes and interventions, we quantified racial disparities for sPTB and mPTB, and we characterized the geographic patterning of these phenotypes, overall and according to race/ethnicity. We examined a pregnancy cohort of 83,952 singleton births at 2 Philadelphia hospitals from 2008-2020, and classified each PTB as sPTB or mPTB. We used binomial regression to quantify the magnitude of racial disparities between non-Hispanic Black and non-Hispanic White individuals, then generated small area estimates by applying a Bayesian model that accounts for small numbers and smooths estimates of PTB risk by borrowing information from neighboring areas. Racial disparities in both sPTB and mPTB were significant (relative risk of sPTB = 1.83, 95% confidence interval: 1.70, 1.98; relative risk of mPTB = 2.20, 95% confidence interval: 2.00, 2.42). The disparity was 20% greater in mPTB than sPTB. There was substantial geographic variation in PTB, sPTB, and mPTB risks and racial disparity. Our findings underscore the importance of distinguishing PTB phenotypes within the context of public health and preventive medicine. Future work should consider social and environmental exposures that may explain geographic differences in PTB risk and disparities.

Place-Based Strategies Addressing Neighborhood Environments to Improve Perinatal and Preterm Infant Outcomes.

Preterm birth (defined as birth <37 weeks of gestation) is a significant health concern globally, with lasting implications for individuals, families, and society. In the United States, high preterm birth rates among Black and low-income populations likely result from differences in environmental exposures. Structural racism and economic disadvantage have led to unequal distribution of polluting industrial sites and roadways across society as well as differential access to health-promoting resources which contribute to preterm birth risk. Once born, preterm infants remain at risk for numerous environmentally responsive adverse health outcomes that affect growth and development throughout childhood and adulthood. In this commentary, we describe associations of neighborhood environments with pregnancy and preterm infant health outcomes and propose strategies to address harmful exposures that affect families across the lifespan.

The Influence of Pandemic-Related Worries During Pregnancy on Child Development at 12 Months.

The COVID-19 pandemic has been linked to increased risk for perinatal anxiety and depression among parents, as well as negative consequences for child development. Less is known about how worries arising from the pandemic during pregnancy are related to later child development, nor if resilience factors buffer negative consequences. The current study addresses this question in a prospective longitudinal design. Data was collected from a sub-study (n = 184) of a longitudinal study of pregnant individuals (total n = 1173). During pregnancy (April 17-July 8, 2020) and the early postpartum period (August 11, 2020-March 2, 2021), participants completed online surveys. At 12 months postpartum (June 17, 2021-March 23, 2022), participants completed online surveys and a virtual laboratory visit, which included parent-child interaction tasks. We found more pregnancy-specific pandemic worries were prospectively related to lower levels of child socioemotional development based on parent report (B = - 1.13, SE = .43, p = .007) and observer ratings (B = - 0.13, SE = .07, p = .045), but not to parent-reported general developmental milestones. Parental emotion regulation in the early postpartum period moderated the association between pregnancy-specific pandemic worries and child socioemotional development such that pregnancy-specific pandemic worries did not relate to worse child socioemotional development among parents with high (B = - .02, SE = .10, t = - .14, p = .89) levels of emotion regulation. Findings suggest the negative consequences of parental worry and distress during pregnancy on the early socioemotional development of children in the context of the COVID-19 pandemic. Results highlight that parental emotion regulation may represent a target for intervention to promote parental resilience and support optimized child development.

Inter-hospital Variation in COVID-19 Era Pediatric Hospitalizations by Age Group and Diagnosis.

BACKGROUND: Mitigation strategies and public responses to coronavirus disease 2019 (COVID-19) varied geographically and may have differentially affected burden of pediatric disease and hospitalization practices. We aimed to quantify hospital-specific variation in hospitalizations during the COVID-19 era. METHODS: Using Pediatric Health Information Systems data from 44 Children's Hospitals, this retrospective multicenter analysis compared hospitalizations of children (1 day-17 years) from the COVID-19 era (March 1, 2020-June 30, 2021) to prepandemic (January 1, 2017-December 31, 2019). Variation in the magnitude of hospital-specific decline between eras was determined using coefficients of variation (CV). Spearman's test was used to assess correlation of variation with community and hospital factors. RESULTS: The COVID-19 era decline in hospitalizations varied between hospitals (CV 0.41) and was moderately correlated with declines in respiratory infection hospitalizations (r = 0.69, P < .001). There was no correlation with community or hospital factors. COVID-19 era changes in hospitalizations for mental health conditions varied widely between centers (CV 2.58). Overall, 22.7% of hospitals saw increased admissions for adolescents, and 29.5% saw increases for newborns 1 to 14 days, representing significant center-specific variation (CV 2.30 for adolescents and 1.98 for newborns). CONCLUSIONS: Pandemic-era change in hospitalizations varied across institutions, partially because of hospital-specific changes in respiratory infections. Residual variation exists for mental health conditions and in groups least likely to be admitted for respiratory infections, suggesting that noninfectious conditions may be differentially and uniquely affected by local policies and hospital-specific practices enacted during the COVID-19 era.

Cervicovaginal Microbial-Immune State and Group B Streptococcus Colonization in Pregnancy.

OBJECTIVE: Maternal colonization with Group B Streptococcus (GBS) is a significant risk factor for serious neonatal morbidity. There are limited data on how the cervicovaginal (CV) microbiota and host immune factor ß-defensin-2 might influence GBS colonization in pregnant individuals. This study sought to determine if the CV microbiota is associated with GBS colonization in pregnant individuals, and if ß-defensin-2 modifies this relationship. STUDY DESIGN: This was a secondary analysis of a prospective cohort study of pregnant individuals with singleton pregnancies who had CV microbiota specimens analyzed at 16 to 20, 20 to 24, and 24 to 28 weeks' gestation, along with a third trimester GBS rectovaginal (RV) culture (n = 492). Microbiota data were analyzed with 16S rRNA gene sequencing and classified into community state types (CSTs). Log-binomial multivariable regression was used to model associations between CST and GBS RV status and to calculate risk ratios. ß-defensin-2, an immune factor known to modulate the relationship between CST and pregnancy outcomes, was examined as an effect modifier. RESULTS: Of 492 individuals, 34.3% were GBS RV + . Compared with individuals with CST I at 16 to 20 weeks, individuals with CST IV-A and CST II had a significantly elevated relative risk of subsequent GBS RV+ status. When stratified by high and low ß-defensin-2 levels, ß-defensin-2 was found to be an effect modifier of the association between CST IV-A and GBS RV+ status. In individuals with low ß-defensin-2 levels, CST VI-A was associated with GBS RV+ status, but among individuals with high ß-defensin-2 levels, there was no such association (interaction p-value = 0.03). CONCLUSION: Pregnant individuals with CV microbiota characterized by CST IV-A and CST II had significantly elevated risk of GBS RV colonization in the third trimester compared with those with CST I, and ß-defensin-2 was an effect modifier of the association between CST IV-A and GBS RV+ status. Future research should investigate if manipulation of the CV microbiota can prevent GBS colonization, thereby reducing intrapartum antibiotic prophylaxis and the risks of neonatal GBS infection. KEY POINTS: · The relationship between the CV microbiota and GBS RV colonization is unknown.. · A Lactobacillus-deficient, anaerobic rich vaginal community, CST IV-A, is associated with increased risk of GBS RV colonization.. · ß-defensin-2 is an effect modifier of the association between CST IV-A and GBS RV+ status..

Associations of neighborhood social vulnerability with emergency department visits and readmissions among infants with bronchopulmonary dysplasia.

OBJECTIVES: To characterize associations of the CDC Social Vulnerability Index (SVI) with medically attended acute respiratory illness among infants with bronchopulmonary dysplasia (BPD). STUDY DESIGN: Retrospective cohort of 378 preterm infants with BPD from a single center. Multivariable logistic regression quantified associations of SVI with medically attended acute respiratory illness, defined as emergency department (ED) visits or hospital readmissions within a year after first hospital discharge. Mediation analysis quantified the extent to which differences in SVI may explain known Black-White disparities in medically attended acute respiratory illness. RESULTS: SVI was associated with medically attended respiratory illness (per SVI standard deviation increment, aOR 1.44, 95% CI: 1.17-1.78). Adjustment for race and ethnicity attenuated the association (aOR 1.27, 95% CI: 0.97-1.64). SVI significantly mediated 31% of the Black-White disparity in ED visits (p = 0.04). CONCLUSIONS: SVI was associated with, and may partially explain racial disparities in, medically attended acute respiratory illness among infants with BPD.

The impact of postpartum social support on postpartum mental health outcomes during the COVID-19 pandemic.

Social support is an influential component of postpartum recovery, adjustment, and bonding, which was disrupted by social distancing recommendations related to the COVID-19 pandemic. This study reports on changes in the availability of social support for postpartum women during the pandemic, investigates how those changes may have contributed to postpartum mental health, and probes how specific types of social support buffered against poor postpartum mental health and maternal-infant bonding impairment. Participants were 833 pregnant patients receiving prenatal care in an urban USA setting and using an electronic patient portal to access self-report surveys at two time points, during pregnancy (April-July 2020) and at ~12 weeks postpartum (August 2020-March 2021). Measures included an assessment of COVID-19 pandemic-related change in social support, sources of social support, ratings of emotional and practical support, and postpartum outcomes including depression, anxiety, and maternal-infant bonding. Overall self-reported social support decreased during the pandemic. Decreased social support was associated with an increased risk of postpartum depression, postpartum anxiety, and impaired parent-infant bonding. Among women reporting low practical support, emotional support appeared to protect against clinically significant depressive symptoms and impaired bonding with the infant. Decreases in social support are associated with a risk for poor postpartum mental health outcomes and impaired maternal-infant bonding. Evaluation and promotion of social support are recommended for healthy adjustment and functioning of postpartum women and families.

Neighborhood Deprivation and Racial Disparities in Early Pregnancy Impaired Glucose Tolerance.

OBJECTIVE: There is mounting evidence that neighborhoods contribute to perinatal health inequity. We aimed (1) to determine whether neighborhood deprivation (a composite marker of area-level poverty, education, and housing) is associated with early pregnancy impaired glucose intolerance (IGT) and pre-pregnancy obesity and (2) to quantify the extent to which neighborhood deprivation may explain racial disparities in IGT and obesity. STUDY DESIGN: This was a retrospective cohort study of non-diabetic patients with singleton births ≥ 20 weeks' gestation from 1 January 2017-31 December 2019 in two Philadelphia hospitals. The primary outcome was IGT (HbA1c 5.7-6.4%) at <20 weeks' gestation. Addresses were geocoded and census tract neighborhood deprivation index (range 0-1, higher indicating more deprivation) was calculated. Mixed-effects logistic regression and causal mediation models adjusted for covariates were used. RESULTS: Of the 10,642 patients who met the inclusion criteria, 49% self-identified as Black, 49% were Medicaid insured, 32% were obese, and 11% had IGT. There were large racial disparities in IGT (16% vs. 3%) and obesity (45% vs. 16%) among Black vs. White patients, respectively (p < 0.0001). Mean (SD) neighborhood deprivation was higher among Black (0.55 (0.10)) compared with White patients (0.36 (0.11)) (p < 0.0001). Neighborhood deprivation was associated with IGT and obesity in models adjusted for age, insurance, parity, and race (aOR 1.15, 95%CI: 1.07, 1.24 and aOR 1.39, 95%CI: 1.28, 1.52, respectively). Mediation analysis revealed that 6.7% (95%CI: 1.6%, 11.7%) of the Black-White disparity in IGT might be explained by neighborhood deprivation and 13.3% (95%CI: 10.7%, 16.7%) by obesity. Mediation analysis also suggested that 17.4% (95%CI: 12.0%, 22.4%) of the Black-White disparity in obesity may be explained by neighborhood deprivation. CONCLUSION: Neighborhood deprivation may contribute to early pregnancy IGT and obesity-surrogate markers of periconceptional metabolic health in which there are large racial disparities. Investing in neighborhoods where Black patients live may improve perinatal health equity.

Impact of exposure to air pollution on cervicovaginal microbial communities.

PURPOSE: Vaginal microbial communities can be dominated by anaerobic (community state type IV, CST IV) or Lactobacillus (other CSTs) species. CST IV is a risk factor for spontaneous preterm birth (sPTB) and is more common among Black than White populations. In the US, average air pollution exposures are higher among Black compared to White people and exert systemic health effects. We sought to (1) quantify associations of air pollution, specifically particulate matter <2.5 µm in diameter (PM2.5), with CST IV and (2) explore the extent to which racial disparities in PM2.5 exposure might explain racial differences in the prevalence of CST IV. DESIGN: Methods: We performed a secondary analysis of 566 participants of the Motherhood & Microbiome study. PM2.5 exposures were derived from a machine learning model integrating NASA satellite and EPA ground monitor data. Previously, cervicovaginal swabs from 15 to 20 weeks' gestation were analyzed using 16 S rRNA sequencing and hierarchical clustering assigned CSTs. Multivariable logistic regression models calculated adjusted odds ratios of CST IV (vs. other CSTs) per interquartile range (IQR) increment of PM2.5. Race-stratified and mediation analyses were performed. RESULTS: Higher PM2.5 exposure was associated with CST IV (aOR 1.39, 95% CI 1.02-1.91). Further adjustment for race/ethnicity attenuated the association (aOR 1.34, 95% CI: 0.97-1.83). Black participants (vs. White) had higher median PM2.5 exposure (10.6 vs. 9.6 µg/m3, P < 0.001) and higher prevalence of CST IV (47% vs. 11%, P < 0.001). Mediation analysis revealed that higher PM2.5 exposure may explain 3.9% (P = 0.038) and 3.3% (P = 0.15) of the Black-White disparity in CST IV in unadjusted and adjusted models, respectively. CONCLUSION: PM2.5 was associated with CST IV, a risk factor for sPTB. Additionally, PM2.5 exposure may partially explain racial differences in the prevalence of CST IV. Further research is warranted to discover how environmental exposures affect microbial composition and perpetuate racial health disparities.

Neighborhood Walkability as a Risk Factor for Preterm Birth Phenotypes in Two Philadelphia Hospitals from 2013-2016.

A total of one in ten infants is born preterm in the U.S. with large racial disparities. Recent data suggest that neighborhood exposures may play a role. Walkability-how easily individuals can walk to amenities-may encourage physical activity. We hypothesized that walkability would be associated with a decreased risk of preterm birth (PTB) and that associations would vary by PTB phenotype. PTB can be spontaneous (sPTB) from conditions such as preterm labor and preterm premature rupture of membranes, or medically indicated (mPTB) from conditions such as poor fetal growth and preeclampsia. We analyzed associations of neighborhood walkability (quantified by their Walk Score® ranking) with sPTB and mPTB in a Philadelphia birth cohort (n = 19,203). Given racial residential segregation, we also examined associations in race-stratified models. Walkability (per 10 points of Walk Score ranking) was associated with decreased odds of mPTB (aOR 0.90, 95% CI: 0.83, 0.98), but not sPTB (aOR 1.04, 95% CI: 0.97, 1.12). Walkability was not protective for mPTB for all patients; there was a non-significant protective effect for White (aOR 0.87, 95% CI: 0.75, 1.01), but not Black patients (aOR 1.05, 95% CI: 0.92, 1.21) (interaction p = 0.03). Measuring health effects of neighborhood characteristics across populations is key for urban planning efforts focused on health equity.

Assessing racial residential segregation as a risk factor for severe maternal morbidity.

PURPOSE: To measure associations of area-level racial and economic residential segregation with severe maternal morbidity (SMM). METHODS: We conducted a retrospective cohort study of births at two Philadelphia hospitals between 2018 and 2020 to analyze associations of segregation, quantified using the Index of Concentration at the Extremes (ICE), with SMM. We used stratified multivariable, multilevel, logistic regression models to determine whether associations of ICE with SMM varied by self-identified race or hospital catchment. RESULTS: Of the 25,979 patients (44.1% Black, 35.8% White), 1381 (5.3%) had SMM (Black [6.1%], White [4.4%]). SMM was higher among patients residing outside (6.3%), than inside (5.0%) Philadelphia (P < .001). Overall, ICE was not associated with SMM. However, ICErace (higher proportion of White vs. Black households) was associated with lower odds of SMM among patients residing inside Philadelphia (aOR 0.87, 95% CI: 0.80-0.94) and higher odds outside Philadelphia (aOR 1.12, 95% CI: 0.95-1.31). Moran's I indicated spatial autocorrelation of SMM overall (P < .001); when stratified, autocorrelation was only evident outside Philadelphia. CONCLUSIONS: Overall, ICE was not associated with SMM. However, higher ICErace was associated with lower odds of SMM among Philadelphia residents. Findings highlight the importance of hospital catchment area and referral patterns in spatial analyses of hospital datasets.