Severe maternal morbidity among U.S.- and foreign-born Asian and Pacific Islander women in California

Assessing the relationship between census tract rurality and severe maternal morbidity in California (1997-2018)

PURPOSE

Recent studies have demonstrated an increased risk of severe maternal morbidity (SMM) for people living in rural versus urban counties. Studies have not considered rurality at the more nuanced subcounty census-tract level. This study assessed the relationship between census-tract-level rurality and SMM for birthing people in California.

METHODS

We used linked vital statistics and hospital discharge records for births between 1997 and 2018 in California. SMM was defined by at least 1 of 21 potentially fatal conditions and lifesaving procedures. Rural-Urban Commuting Area codes were used to characterize census tract rurality dichotomously (2-category) and at 4 levels (4-category). Covariates included sociocultural-demographic, pregnancy-related, and neighborhood-level factors. We ran a series of mixed-effects logistic regression models with tract-level clustering, reporting risk ratios and 95% confidence intervals (CIs). We used the STROBE reporting guidelines.

FINDINGS

Of 10,091,415 births, 1.1% had SMM. Overall, 94.3% of participants resided in urban/metropolitan and 5.7% in rural tracts (3.9% micropolitan, 0.9% small town, 0.8% rural). In 2-category models, the risk of SMM was 10% higher for birthing people in rural versus urban tracts (95% CI: 6%, 13%). In 4-category models, the risk of SMM was 16% higher in micropolitan versus metropolitan tracts (95% CI: 12%, 21%).

CONCLUSION

The observed rurality and SMM relationship was driven by living in a micropolitan versus metropolitan tract. Increased risk may result from resource access inequities within suburban areas. Our findings demonstrate the importance of considering rurality at a subcounty level to understand locality-related inequities in the risk of SMM.

Validation of a measure of hospital maternal level of care for the United States

BACKGROUND

Lack of a validated assessment of maternal risk-appropriate care for use in population data has prevented the existing literature from quantifying the benefit of maternal risk-appropriate care. The objective of this study was to develop a measure of hospital maternal levels of care based on the resources available at the hospital, using existing data available to researchers.

METHODS

This was a secondary data analysis. The sample was abstracted from the American Hospital Association Annual Survey Database for 2018. Eligibility was limited to short-term acute general hospitals that reported providing maternity services as measured by hospital reporting of an obstetric service level, obstetric services, or birthing rooms. We aligned variables in the database with the ACOG criteria for each maternal level of care, then built models that used the variables to measure the maternal level of care. In each iteration, the distribution of hospitals was compared to the distribution in the CDC Levels of Care Assessment Tool Validation Pilot, assessing agreement with the Wilson Score for proportions for each level of care. Results were compared to hospital self-report in the database and measurement reported with another published method.

RESULTS

The sample included 2,351 hospitals. AHA variables were available to measure resources that align with ACOG Levels 1, 2, and 3. Overall, 1219 (51.9%) of hospitals reported resources aligned with Maternal Level One, 816 (34.7%) aligned with maternal level two, and 202 (8.6%) aligned with maternal level Three. This method overestimates the prevalence of hospitals with maternal level one compared to the CDC measurement of 36.1% (Mean 52.9%; 95% CI47.2%-58.7%), and likely includes hospitals that would not qualify as level one if all resources required by the ACOG guidelines could be assessed. This method underestimates the prevalence of hospitals with maternal critical care services (Level 3 or 4) compared to CDC measure of 12.1% (Mean 8.1%; 95%CI 6.2% - 10.0%) but is an improvement over hospital self-report (24.7%) and a prior published method (32.3%).

CONCLUSIONS

This method of measuring maternal level of care allows researchers to investigate the value of perinatal regionalization, risk-appropriate care, and hospital differences among the three levels of care. This study identified potential changes to the American Hospital Association Annual Survey that would improve identification of maternal levels of care for research.

Racial and Ethnic Disparities in Anemia and Severe Maternal Morbidity

OBJECTIVE

To evaluate antepartum anemia prevalence by race and ethnicity, to assess whether such differences contribute to severe maternal morbidity (SMM), and to estimate the contribution of antepartum anemia to SMM and nontransfusion SMM by race and ethnicity.

METHODS

We conducted a population-based cohort study using linked vital record and birth hospitalization data for singleton births at or after 20 weeks of gestation in California from 2011 through 2020. Pregnant patients with hereditary anemias, out-of-hospital births, unlinked records, and missing variables of interest were excluded. Antepartum anemia prevalence and trends were estimated by race and ethnicity. Centers for Disease Control and Prevention criteria were used for SMM and nontransfusion SMM indicators. Multivariable logistic regression modeling was used to estimate risk ratios (RRs) for SMM and nontransfusion SMM by race and ethnicity after sequential adjustment for social determinants, parity, obstetric comorbidities, delivery, and antepartum anemia. Population attributable risk percentages were calculated to assess the contribution of antepartum anemia to SMM and nontransfusion SMM by race and ethnicity.

RESULTS

In total, 3,863,594 births in California were included. In 2020, Black pregnant patients had the highest incidence of antepartum anemia (21.5%), followed by Pacific Islander (18.2%), American Indian-Alaska Native (14.1%), multiracial (14.0%), Hispanic (12.6%), Asian (10.6%), and White pregnant patients (9.6%). From 2011 to 2020, the prevalence of anemia increased more than100% among Black patients, and there was a persistent gap in prevalence among Black compared with White patients. Compared with White patients, the adjusted risk for SMM was high among most racial and ethnic groups; adjustment for anemia after sequential modeling for known confounders decreased SMM risk most for Black pregnant patients (approximated RR 1.47, 95% CI 1.42-1.53 to approximated RR 1.27, 95% CI 1.22-1.37). Compared with White patients, the full adjusted nontransfusion SMM risk remained high for most groups except Hispanic and multiracial patients. Within each racial and ethnic group, the population attributable risk percentage for antepartum anemia and SMM was highest for multiracial patients (21.4%, 95% CI 17.5-25.0%), followed by Black (20.9%, 95% CI 18.1-23.4%) and Hispanic (20.9%, 95% CI 19.9-22.1%) patients. The nontransfusion SMM population attributable risk percentages for Asian, Black, and White pregnant patients were less than 8%.

CONCLUSION

Antepartum anemia, most prevalent among Black pregnant patients, contributed to disparities in SMM by race and ethnicity. Nearly one in five to six SMM cases among Black, Hispanic, American Indian-Alaska Native, Pacific Islander, and multiracial pregnant patients is attributable in part to antepartum anemia.

The "Birth-Centered Outcomes Research Engagement (B-CORE) in Medi-Cal" Project: Community-Generated Recommendations to Decrease Maternal Mortality and Severe Maternal Morbidity

BACKGROUND

Through applied research and health care quality improvement, California has achieved a maternal mortality (MM) rate significantly lower than that measured nationally. However, Medicaid (Medi-Cal)-insured births in the state continue to experience disproportionate shares of MM and severe maternal morbidity (SMM), which often precedes death. Failure to engage the Medi-Cal community in this work may impede efforts to increase equity.

METHODS

This community engagement project used deliberative democracy methods to engage stakeholders with lived experience in California's Medi-Cal perinatal care system to generate an actionable and specific agenda of recommendations to decrease MM and SMM in the Medi-Cal population.

FINDINGS

A total of 37 Medi-Cal stakeholders-representing birthing people, providers, health plan administrators, and advocates-participated in longitudinal co-learning sessions on the topics of MM/SMM in Medi-Cal. Most of these stakeholders (75.7%) then participated in deliberation sessions. Deliberation recommendations fell into five distinct categories: Medi-Cal perinatal covered benefits, data collection and dissemination, patient experience and its link to care quality, Medi-Cal reimbursement rates, and accountability with respect to racism in perinatal care. Stakeholders identified the Medi-Cal system actors best positioned to implement specific recommendations to directly impact MM/SMM.

CONCLUSIONS

This project demonstrates the feasibility and success of using deliberative democracy methods to generate local and community-generated solutions to critical problems in health equity. Active and engaged stakeholders were keen to identify both immediate actions and long-term research and quality improvement paradigm shifts to support birth equity in Medi-Cal.

Remapping racial and ethnic inequities in severe maternal morbidity: The legacy of redlining in California

BACKGROUND

Historical mortgage redlining, a racially discriminatory policy designed to uphold structural racism, may have played a role in producing the persistently elevated rate of severe maternal morbidity (SMM) among racialised birthing people.

OBJECTIVE

This study examined associations between Home-Owner Loan Corporation (HOLC) redlining grades and SMM in a racially and ethnically diverse birth cohort in California.

METHODS

We leveraged a population-based cohort of all live hospital births at ≥20 weeks of gestation between 1997 and 2017 in California. SMM was defined as having one of 21 procedures and diagnoses, per an index developed by Centers for Disease Control and Prevention. We characterised census tract-level redlining using HOLC's security maps for eight California cities. We assessed bivariate associations between HOLC grades and participant characteristics. Race and ethnicity-stratified mixed effects logistic regression models assessed the risk of SMM associated with HOLC grades within non-Hispanic Black, Asian/Pacific Islander, American Indian/Alaskan Native and Hispanic groups, adjusting for sociodemographic information, pregnancy-related factors, co-morbidities and neighbourhood deprivation index.

RESULTS

The study sample included 2,020,194 births, with 24,579 cases of SMM (1.2%). Living in a census tract that was graded as "Hazardous," compared to census tracts graded "Best" and "Still Desirable," was associated with 1.15 (95% confidence interval [CI] 1.03, 1.29) and 1.17 (95% CI 1.09, 1.25) times the risk of SMM among Black and Hispanic birthing people, respectively, independent of sociodemographic factors. These associations persisted after adjusting for pregnancy-related factors and neighbourhood deprivation index.

CONCLUSIONS

Historical redlining, a tool of structural racism that influenced the trajectory of neighbourhood social and material conditions, is associated with increased risk of experiencing SMM among Black and Hispanic birthing people in California. These findings demonstrate that addressing the enduring impact of macro-level and systemic mechanisms that uphold structural racism is a vital step in achieving racial and ethnic equity in birthing people's health.

Risk factors and pregnancy outcomes vary among Asian American, Native Hawaiian, and Pacific Islander individuals giving birth in California

OBJECTIVE

To compare frequencies of risk factors and pregnancy outcomes in ethnic groups versus the combined total of Asian American, Native Hawaiian, and Pacific Islander (AANHPI) populations.

METHODS

Using linked birth and fetal death certificate and maternal hospital discharge data (California 2007-2018), we estimated frequencies of 15 clinical and sociodemographic exposures and 11 pregnancy outcomes. Variability across 15 AANHPI groups was compared using a heat map and compared to frequencies for the total group (n = 904,232).

RESULTS

AANHPI groups varied significantly from each other and the combined total regarding indicators of social disadvantage (e.g., range for high school-level educational or less: 6.4% Korean-55.8% Samoan) and sociodemographic factors (e.g., maternal age <20 years: 0.2% Chinese-8.8% Guamanian) that are related to adverse pregnancy outcomes. Perinatal outcomes varied significantly (e.g., severe maternal morbidity: 1.2% Korean-1.9% Filipino). No single group consistently had risk factors or outcome prevalence at the extremes, i.e., no group was consistently better or worse off across examined factors.

CONCLUSIONS

Substantial variability in perinatal risk factors and outcomes exists across AANHPI groups. Aggregation into "AANHPI" is not appropriate for outcome reporting.

Severe Maternal Morbidity and Maternal Mortality in Women With Intellectual and Developmental Disabilities

INTRODUCTION

Despite increased attention on severe maternal morbidity and maternal mortality, scant research exists on adverse maternal outcomes in women with disabilities. This study compares the rates of severe maternal morbidity and maternal mortality in women with and without intellectual and developmental disabilities.

METHODS

This study used 2004-2017 Healthcare Cost and Utilization Project Nationwide Inpatient Sample data. Analyses were conducted in 2019‒2020. The risk of severe maternal morbidity with and without blood transfusion and maternal mortality during delivery among women with and without intellectual and developmental disabilities were compared using modified Poisson regression analysis.

RESULTS

This study identified 32,324 deliveries to women with intellectual and developmental disabilities. Per 10,000 deliveries, 566 deliveries with severe maternal morbidity occurred in women with intellectual and developmental disabilities compared with 239 in women without intellectual and developmental disabilities. Women with intellectual and developmental disabilities had greater risk of both severe maternal morbidity (risk ratio=2.36, 95% CI=2.06, 2.69) and nontransfusion severe maternal morbidity (risk ratio=2.95, 95% CI=2.42, 3.61) in unadjusted analyses, which was mitigated in adjusted analyses for sociodemographic characteristics (risk ratio=1.74, 95% CI=1.47, 2.06; risk ratio=1.85, 95% CI=1.42, 2.41) and the expanded obstetric comorbidity index (risk ratio=1.23, 95% CI=1.04, 1.44; risk ratio=1.31, 95% CI=1.02, 1.68). The unadjusted incidence of maternal mortality in women with intellectual and developmental disabilities was 284 per 100,000 deliveries, nearly 4-fold higher than in women without intellectual and developmental disabilities (69 per 100,000 deliveries; risk ratio=4.07, 95% CI=2.04, 8.12), and the risk remained almost 3-fold higher after adjustment for sociodemographic characteristics (risk ratio=2.86, 95% CI=1.30, 6.29) and the expanded obstetric comorbidity index (risk ratio=2.30, 95% CI=1.05, 5.29).

CONCLUSIONS

Women with intellectual and developmental disabilities are at increased risk of severe maternal morbidity and maternal mortality. These findings underscore the need for enhanced monitoring of the needs and maternal outcomes of women with intellectual and developmental disabilities in efforts to improve maternal health.