Maternal Morbidity and Mortality in Multiple Pregnancy

描述（由申请人提供）：2002年，美国有超过132，500例多胞胎，是有史以来最高的记录。自1980年以来，多胞胎的发生率急剧上升，双胞胎增加了83%，三胞胎和更高顺序的出生（四胞胎和五胞胎）增加了453%以上。与单胎婴儿相比，多胎婴儿更有可能早产和极低出生体重，这是导致其发病率和死亡率过高的重要因素。相比之下，对多胎妊娠如何影响母亲健康的了解要少得多。基于医院的研究报告先兆子痫，妊娠糖尿病，PPROM，早产，以及危及生命的并发症和产妇入院重症监护的发生率较高。然而，这些研究受到样本量小和经常未能控制母亲年龄和产次等混杂因素的限制。本申请中提出的研究目的是填补这一知识空白，方法是利用国家生命统计数据，按产妇年龄、种族和胎次制定多人特定发病率和死亡率风险。本研究将使用三个国家数据集：1995-2000年匹配多胎出生数据集（双胎和三胎妊娠的产妇发病率），1990-2000年活产数据集（单胎妊娠产妇发病率）和1990-2000年多种死亡原因死亡率数据集（单胎、双胎和三胎妊娠中的孕产妇死亡），研究样本为42，736，904例单胎活产，322，758对双胞胎，12，133对三胞胎和3，580例孕产妇死亡。还将分析根据2003年修订的活产证明另外811 929例怀孕（799 422例单胎、11 999例双胎和508例三胎）的数据，以确定按受孕方法分列的产妇发病率和死亡率风险。这一建议的主要假设是，较高的多元性是影响产妇发病率和死亡率的主要因素，而产妇年龄较大和经产次数过多则进一步强化了这一因素。

DESCRIPTION (provided by applicant): In 2002, there were more than 132,500 multiple births in the United States, the highest number ever recorded. The incidence of multiple births has risen dramatically since 1980, with an 83% increase in twins and more than a 453% increase in triplets and higher-order births (quadruplets and quintuplets). Compared to singletons, infants of multiple births are much more likely to be born early preterm and very low birthweight, important well-documented factors that contribute to their excess morbidity and mortality. In contrast, far less is known about how multiple pregnancies affects the health of the mother. Hospital-based studies report higher rates of preeclampsia, gestational diabetes, PPROM, preterm labor, as well as life threatening complications and maternal admission to intensive care. These studies are limited, though, by their small sample sizes and frequent failure to control for the confounding factors of maternal age and parity. The objective of the study proposed in this application is to fill this knowledge gap by using national vital statistics data to formulate plurality-specific morbidity and mortality risks by maternal age, race, and parity. Three national data sets will be used for this study: the Matched Multiple Birth Data Set for 1995-2000 (for maternal morbidity in twin and triplet pregnancies), the Live Birth Data Set for 1990-2000 (for maternal morbidity in singleton pregnancies), and the Mortality Multiple Cause of Death Data Set for 1990-2000 (for maternal deaths in singleton, twin, and triplet pregnancies), for a study sample of 42,736,904 singleton live births, 322,758 matched sets of twins, 12,133 matched sets of triplets, and 3,580 maternal deaths. Data on an additional 811,929 pregnancies (799,422 singletons, 11,999 twins, and 508 triplets) based on the 2003 revision of the live birth certificate will also be analyzed to determine maternal morbidity and mortality risks by method of conception. The main hypothesis of this proposal is that higher plurality is the predominant factor affecting maternal morbidity and mortality, further potentated by older maternal age and primiparity.