Kaiser Permanente Northern California's Division of Research.
Kaiser Permanente Northern California's Division of Research.
Am J Obstet Gynecol MFM. 2022 May;4(3):100608. doi: 10.1016/j.ajogmf.2022.100608. Epub 2022 Mar 4.
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.
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.
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.
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.
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.
早产儿和产妇心血管代谢风险因素存在明显的种族和民族差异，这些差异可能与系统性种族主义有关。然而，目前尚不清楚心血管代谢风险因素在多大程度上导致少数族裔人群的早产儿比例较高。
本研究旨在评估早产儿亚型的种族和民族差异，以及产妇心血管代谢风险因素作为产妇种族和民族与早产儿亚型之间关联的中介因素的作用。
这是一项对 2011 年至 2018 年间 295210 例单胎活产的回顾性队列研究。早产儿亚型定义为医学指征性早产和自发性早产。使用泊松回归和稳健标准误差提供早产亚型的相对风险和 95%置信区间的估计值。因果中介分析使用逻辑回归模型估计产妇心血管代谢风险因素的自然直接和自然间接（中介）效应。
与白人个体相比，黑人、亚裔和西班牙裔个体发生医学指征性早产的风险增加（1.45，1.30-1.61；1.21，1.12-1.31；1.13，1.05-1.22，分别）（风险比，95%置信区间，分别）和自发性早产（1.20，1.08-1.34；1.34，1.26-1.43；1.16，1.08-1.23），独立于既定的风险因素。心血管代谢风险因素在多大程度上中介了种族和民族（在单独的分析中，每个组与白人相比）与早产儿亚型之间的关联，因种族和民族而异。高血压疾病在黑人种族与医学指征性早产之间的关联中中介了 30.1%，但在其他种族或自发性早产中没有中介。任何妊娠期间的葡萄糖异常都是亚裔（分别为 65.8%和 13.9%）和西班牙裔（分别为 17.3%和 11.9%）种族与医学指征性早产和自发性早产之间的中介因素，但不是黑人种族的中介因素。超重或肥胖在黑人（15.5%）和西班牙裔（25.1%）个体中与医学指征性早产和自发性早产（西班牙裔个体中 10.7%）之间的关联中是中介因素，但在亚裔个体中不是中介因素。
黑人、亚裔和西班牙裔个体发生早产的风险增加。产妇心血管代谢风险因素部分中介了种族和民族与早产儿亚型之间的关联，但程度因种族和民族而异。这些发现表明，改善和减少不同种族和民族之间心血管代谢健康差异的策略可能会减少早产的差异。
