Severe maternal morbidity: A population-based study of an expanded measure and associated factors

Severe maternal morbidity conditions such as sepsis, embolism and cardiac arrest during the delivery hospitalization period can lead to extended length of hospital stays, life-long maternal health problems, and high medical costs. Most importantly, these conditions also contribute to the risk of maternal death. This population-based observational study proposed and evaluated the impact of expanding the Centers for Disease Control and Prevention (CDC) measure of severe maternal morbidity by including additional comorbidities and intensive care admissions during delivery hospitalizations and examined associated factors. A New York State linked hospitalization and birth record database was used. Study participants included all New York State female residents, ages 10 to 55 years, who delivered a live infant in a New York acute care hospital between 2008 and 2013, inclusive. Incidence trends for both severe maternal morbidity measures were evaluated longitudinally. Associations between covariates and the two severe maternal morbidity measures were examined with logistic regression models, solved using generalized estimating equations and stratified by method of delivery. The New York expanded severe maternal morbidity measure identified 34,478 cases among 1,352,600 hospital deliveries (estimated incidence 2.55%) representing a 3% increase in the number of cases compared to the CDC measure. Both estimates increased over the study period (p<0.001). Covariates with an odds ratio > 1.5 included most measured comorbidities (e.g., pregnancy-induced hypertension, placentation disorder), multiple births, preterm birth, no prenatal care, hospitalization prior to delivery, higher levels of perinatal care birthing facilities and race/ethnicity. Expanding the measure for severe maternal morbidity during delivery to capture intensive care admissions provides a more sensitive estimate of disease burden. Perinatal regionalization in New York appears effective in routing high risk pregnancies to higher levels of perinatal care birthing facilities.

分娩住院期间发生的脓毒症、栓塞症、心搏骤停等严重孕产妇发病（severe maternal morbidity）事件，可导致住院时长延长、终身性产妇健康问题以及高额医疗费用。更为关键的是，此类事件还会增加孕产妇死亡风险。本项基于人群的观察性研究，通过纳入分娩住院期间新增的合并症与重症监护收治情况，对扩充美国疾病控制与预防中心（Centers for Disease Control and Prevention, CDC）严重孕产妇发病评估标准的效果进行了评价，并对相关影响因素展开了分析。研究采用纽约州住院分娩关联记录数据库。研究对象为2008年至2013年（含首尾两年）间，在纽约州急症医院分娩活产儿的所有10至55岁女性居民。研究对两种严重孕产妇发病评估标准的发病率趋势进行了纵向分析；同时采用广义估计方程（generalized estimating equations）求解的逻辑回归模型（logistic regression models），按分娩方式分层，分析了协变量与两种严重孕产妇发病评估标准之间的关联。经扩充后的纽约州严重孕产妇发病评估标准，在1352600例住院分娩病例中识别出34478例（估算发病率为2.55%），相较于CDC标准的病例数增加了3%。两种评估标准的病例数均在研究周期内呈上升趋势（p<0.001）。优势比（odds ratio, OR）大于1.5的协变量包括多数纳入统计的合并症（如妊娠高血压疾病、胎盘发育异常）、多胎妊娠、早产、未接受产前检查、分娩前住院、高等级围产期护理分娩机构以及种族/族裔因素。扩充分娩期严重孕产妇发病评估标准以纳入重症监护收治情况，可获得更为灵敏的疾病负担评估结果。纽约州的围产期区域化医疗模式，似乎可有效将高风险妊娠患者转诊至更高等级的围产期护理分娩机构。