Severe Maternal Morbidity: An Investigation of Racial-Ethnic Disparities, Social Disadvantage & Maternal Weight

摘要： 严重孕产妇发病率(SMM)包括在分娩或产后发生的对产妇健康和生存的严重威胁。根据美国疾病控制与预防中心开发的SMM指数，SMM的患病率在1998-2011年间翻了一番，目前美国每年有65,000名女性受到影响。产妇健康对妇女照顾子女的能力和一生的健康至关重要，但我们对SMM的病因了解有限。这项建议涉及SMM研究的三个关键和未被充分研究的领域：种族/民族差异、母亲体重和社会劣势。SMM的种族/民族差异及其促成条件是众所周知的--与非西班牙裔白人相比，非西班牙裔黑人患SMM的风险往往高出2倍，而在拉美裔和亚洲人中，SMM的风险高出1.5倍。对这些差异的解释尚不清楚，但初步 有证据表明，母亲的体重和社会劣势可能是原因之一。在美国，25%的女性在怀孕时肥胖，一半的女性在怀孕期间体重超标，25%的女性体重保持在10磅。产后，但这会因种族而异。一些研究表明肥胖与SMM有关，但很少有人研究肥胖的严重程度、体重不足状况或体重变化。社会劣势在非白人中比白人更常见，并与无数围产期结局相关，但几乎没有研究探讨其对SMM的贡献。异常高和低的母亲体重和体重增加最有可能发生在社会处境不利的妇女中，但它们对SMM的相互关联影响尚未被研究。我们的目标是通过分析2007-2014年间加州发生的400万新生儿，增加对SMM的生物和社会决定因素及其种族/民族差异的理解。这些数据包括生命记录和母婴医院从怀孕到产后的出院数据。结果将包括导致SMM的最常见情况-产后出血、子痫/严重先兆子痫、部分心血管疾病和脓毒症-以及CDC开发的SMM指数。 具体目标是：1)检查母亲体重状况与前、中、后之间的关系 这项工作的目的是：1)审查患有SMM的孕妇的情况，以及这些指标是否因种族/族裔而有所改变；2)审查多层次(个人、家庭、邻里)社会劣势指标与SMM总体和按种族/族裔的关系(目标2a)，以及这些关系在多大程度上受母亲体重状况的影响(目标2b)；以及3)调查产妇体重状况和社会劣势对SMM人口负担及其种族/族裔差异的影响。这项拟议的研究将通过研究母亲体重、社会劣势、种族/民族差异和SMM之间的复杂关系而开辟新的天地。这些知识对于制定有效的公共卫生和临床干预措施以减少SMM及其差异至关重要，包括对产妇体重的指导方针。

ABSTRACT  Severe Maternal Morbidity (SMM) includes serious threats to maternal health and survival that occur at delivery or postpartum. Based on the SMM index developed by CDC that focuses on the most life-­threatening conditions and complications, the prevalence of SMM doubled from 1998-­2011 and currently affects >65,000 women in the U.S. each year. Maternal health is essential to a woman’s ability to care for her children and to her health over her life course, yet our understanding of causes of SMM is limited. This proposal addresses three key and understudied areas of research for SMM: racial/ethnic disparities, maternal weight, and social disadvantage. Racial/ethnic disparities in SMM and its contributing conditions are well known – risk of SMM tends to be up to 2-­fold higher among non-­Hispanic blacks and 1.5-­fold higher among Hispanics and Asians, relative to non-­Hispanic whites. The explanation for these disparities is unknown, but preliminary evidence suggests that maternal weight and social disadvantage may contribute. In the U.S., 25% of women are obese at conception, half gain excessive weight during pregnancy, and 25% retain >10 lb. postpartum, but this varies by race-­ethnicity. Some studies suggest an association of obesity with SMM, but few have examined severity of obesity, underweight status, or weight change. Social disadvantage is much more common among non-­whites than whites and associated with myriad perinatal outcomes, but almost no studies have examined its contribution to SMM. Unusually high and low maternal weight and weight gain are most likely among socially disadvantaged women, but their inter-­related impacts on SMM have not been studied. Our goal is to increase understanding of biologic and social determinants of SMM and its racial/ethnic disparities, by analyzing 4 million births that occurred in California from 2007-­2014. The data include vital records and mother and infant hospital discharge data from pregnancy through postpartum. Outcomes will include the most common conditions that contribute to SMM – postpartum hemorrhage, eclampsia/severe preeclampsia, select cardiovascular conditions, and sepsis – as well as the SMM index developed by CDC. The Specific Aims are: 1) Examine associations of maternal weight status before, during, and between pregnancies with SMM and whether they are modified by race/ethnicity; 2) Examine associations of multi-­level (individual, household, neighborhood) indicators of social disadvantage with SMM, overall and by race/ethnicity (Aim 2a), and the extent to which these relationships are mediated by maternal weight status (Aim 2b); and 3) Investigate the contribution of maternal weight status and social disadvantage to the population burden of SMM and its racial/ethnic disparities. The proposed research will break new ground by studying the complex relationships among maternal weight, social disadvantage, racial/ethnic disparities, and SMM. This knowledge is essential to the development of effective public health and clinical interventions to reduce SMM and its disparities, including guidelines for maternal weight.