Strategies to reduce disparities in maternal morbidity and mortality: The role of obesity and metabolic disease

Racial and Socioeconomic Disparities in Preconception Health Risk Factors and Access to Care

Background: Black birthing people have significantly higher risks of maternal mortality and morbidity compared with White people. Preconception chronic conditions increase the risk of adverse pregnancy outcomes, yet little is known about disparities in preconception health. This study applies an intersectional framework to examine the simultaneous contributions of racial marginalization and economic deprivation in determining disparities in preconception risk factors and access to care. Methods: Using data from the Pregnancy Risk Assessment Monitoring System, 2016-2020 (N = 123,697), we evaluated disparities by race and income in self-reported preconception hypertension, diabetes, obesity, depression, and smoking, as well as preconception insurance coverage and utilization of health care. We estimated linear regression models and calculated predicted probabilities. Results: Black respondents experienced higher probabilities of preconception obesity and high blood pressure at every income level compared with White respondents. Higher income did not attenuate the probability of obesity for Black respondents (linear trend p = 0.21), as it did for White respondents (p < 0.001). Conversely, while White respondents with low income were at higher risk of preconception depression and smoking than their Black counterparts, higher income was strongly associated with reduced risk, with significantly steeper reductions for White compared with Black respondents (difference in trends p < 0.001 for both risk factors). White respondents had higher probabilities of utilizing preconception care across all income levels, despite similar probabilities of insurance coverage. Conclusions: Higher income does not protect against the risk of preconception obesity and other preconception risk factors for Black birthing people as it does for White birthing people. Results point to the need to consider multiple forms of intersecting structural factors in policy and intervention research to improve preconception and maternal health.

Contribution of maternal cardiometabolic risk factors to racial-ethnicity disparities in preterm birth subtypes

BACKGROUND

There are recognized racial-ethnic disparities in preterm birth and in maternal cardiometabolic risk factors likely linked to systemic racism. However, it is unclear the extent to which cardiometabolic risk factors contribute to the higher rates of preterm birth among minoritized populations.

OBJECTIVE

This study aimed to evaluate racial-ethnic disparities in preterm birth subtypes and the role of maternal cardiometabolic risk factors as mediators of the association between maternal race-ethnicity and preterm birth subtypes.

STUDY DESIGN

This was a retrospective cohort study of 295,210 singleton live births from 2011 to 2018. Preterm birth subtypes were defined as medically indicated and spontaneous preterm birth. Poisson regression with robust standard errors were used to provide estimates of the relative risks and 95% confidence intervals for preterm birth subtypes. Causal mediation analysis used logistic regression models to estimate the natural direct and natural indirect (mediated) effects of maternal cardiometabolic risk factors.

RESULTS

Compared with White individuals, Black, Asian, and Hispanic individuals were at increased risk for having both medically indicated preterm birth (1.45, 1.30-1.61; 1.21, 1.12-1.31; and 1.13, 1.05-1.22, respectively) (risk ratios, 95% confidence intervals, respectively) and spontaneous preterm birth (1.20, 1.08-1.34; 1.34, 1.26-1.43; and 1.16, (1.08-1.23), independent of established risk factors. The extent to which cardiometabolic risk factors mediated the associations between race-ethnicity (each group vs White in separate analyses) and preterm birth subtypes varied by race-ethnicity. Hypertensive disorders mediated 30.1% of the association between Black race-ethnicity and medically indicated preterm birth, but it did not mediate the association for other racial-ethnic groups or for spontaneous preterm birth. Any glucose disorder in pregnancy was a mediator of medically indicated preterm birth and spontaneous preterm birth for Asian (65.8% and 13.9%, respectively) and Hispanic (17.3% and 11.9%) race-ethnicity but not for Black race-ethnicity. Overweight or obesity mediated the association between race-ethnicity and medically indicated preterm birth (15.5% among Black individuals and 25.1% among Hispanic individuals) and spontaneous preterm birth (10.7% among Hispanic individuals) but was not a mediator among Asian individuals.

CONCLUSION

Black, Asian, and Hispanic individuals are at increased risk for preterm birth. Maternal cardiometabolic risk factors partially mediate the associations between race-ethnicity and preterm birth subtypes but the extent varies by race-ethnicity. These findings suggest that strategies that improve and diminish differences in cardiometabolic health between race-ethnicity populations may diminish disparities in preterm birth.

Racial and Ethnic Disparities in Health Care and Health Outcomes for Pregnant Women With Diabetes

This article summarizes the current literature on racial and ethnic differences among women with diabetes in pregnancy. The PubMed, Scopus, CINAHL, and Embase databases were searched for original qualitative or quantitative studies published in English from January 1, 2009, to May 31, 2020. Consensus statements were excluded. Results of this synthesis indicate that racial and ethnic differences exist among pregnant women with diabetes, including social determinants of health, disparities in maternity care and perinatal care, and maternal and neonatal health outcomes. Health care providers should implement tailored interventions that specifically target racial and ethnic disparities in maternal and neonatal health to promote health equity in pregnant women with diabetes and their offspring, including later in life.

Mediating Effects of Cardiometabolic Risk Factors on the Association Between Maternal Race-Ethnicity and Cesarean Delivery Among Low-Risk Women

Background: While racial-ethnic disparities in cesarean delivery rates among nulliparous women delivering a term singleton in the vertex position (NTSV) exist, it remains unclear the extent to which potentially modifiable maternal cardiometabolic risk factors (obesity, maternal hyperglycemia and hypertensive disorders) underlie these disparities. We examined race-ethnicity and risk of NTSV cesarean deliveries and whether the associations were mediated by maternal cardiometabolic risk factors. Materials and Methods: A cohort study of 62,048 NTSV deliveries in Kaiser Permanente Northern California. The outcome was cesarean delivery. Results: Black, Asian, and Hispanic women were at increased risk of having a NTSV cesarean delivery compared with White women (relative risks and 95% confidence intervals: 1.37 [1.28-1.45]; 1.11 [1.07-1.16]; 1.12 [1.07-1.16], respectively), independent of established risk factors and prenatal care utilization. The extent to which cardiometabolic risk factors mediated the associations between race-ethnicity (each group vs. White, in separate analyses) and NTSV cesarean delivery varied by race-ethnicity. Maternal overweight/obesity (body mass index ≥25.0) mediated the association between Black and Hispanic race-ethnicity and NTSV cesarean delivery (21.1% [15.8-26.4] and 24.7% [14.6-34.8, respectively), but not for Asian race. Maternal hyperglycemia (gestational diabetes mellitus or preexisting diabetes) mediated the association between Asian and Hispanic race and NTSV cesarean delivery (18.5% [9.8-27.2] and 9.8% [5.0-14.7], respectively), but not for Black race. Hypertensive disorders mediated 3.2% (0.70-5.8) of the association between Black race and cesarean delivery, but not for other race-ethnicities. Conclusion: Black, Asian, and Hispanic women are at increased risk for NTSV cesarean deliveries. Maternal cardiometabolic risk factors only partially mediate the associations between race-ethnicity and NSTV cesarean deliveries.