Maternal Morbidity and Mortality in Multiple Pregnancy

描述（由申请人提供）：2002年，美国有超过132,500个多胞胎，这是有记录以来的最高数字。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分娩（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出生体重过低，这是导致其高发病率和高死亡率的重要因素。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了更高的先兆子痫，妊娠糖尿病，PPROM，早产，以及危及生命的并发症和孕产妇入住重症监护的发生率。然而，这些研究的局限性在于样本量小，而且经常无法控制产妇年龄和胎次等混杂因素。本申请中提出的研究目的是通过使用国家生命统计数据来制定按产妇年龄、种族和胎次划分的多胎特异性发病率和死亡率风险，从而填补这一知识空白。本研究将使用三个国家数据集：1995-2000年的匹配多胞胎数据集（双胎和三胞胎妊娠的孕产妇发病率）、1990-2000年的活产数据集（单胎妊娠的孕产妇发病率）和1990-2000年的多死因死亡率数据集（单胎、双胎和三胞胎妊娠的孕产妇死亡率），研究样本包括42,736,904例单胎活产、322,758对匹配双胞胎、12,133对匹配三胞胎和3,580例孕产妇死亡。根据2003年修订的活产证明，还将分析另外811,929例妊娠（799,422例单胎、11,999例双胞胎和508例三胞胎）的数据，以确定不同受孕方法的产妇发病率和死亡率风险。这一建议的主要假设是，较高的生育率是影响产妇发病率和死亡率的主要因素，高龄产妇和初产进一步加强了这一因素。

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.