Identifying determinants of birth outcomes in South America

描述（由申请人提供）：出生体重、胎龄和宫内生长（IUG）是重要的出生结果，对未来的健康有重要贡献。不良后果包括低出生体重（LBW）、早产和IUGR限制（IUGR）大大增加了死亡和残疾的风险。在全世界每年发生的400万新生儿死亡中，约28%与早产有关，约80%发生在低体重婴儿中。低出生体重和早产是常见的结果，并且在过去二十年中呈上升趋势——全世界有16%的婴儿是低出生体重出生的。这些结果的病因在很大程度上仍然未知，但一些环境、行为和遗传风险被认为是通过独立和相互作用参与的。关于南美洲出生结果的可靠研究相对较少，而且大多数先前的研究都依赖于有限的病例对照样本以及相当简单的统计技术，这些技术极易受到偏倚的影响。本研究旨在通过拉丁美洲先天性异常合作研究（ECLAMC）招募的来自8个南美国家（超过10万名新生儿）的独特和大量非畸形婴儿出生样本，通过独立或相互作用，获得对不良出生结果发生率的可靠估计，并确定导致这些结果的健康、人口、行为和社会经济风险因素。这些样本是在大约90家医院采用相同的抽样和数据收集策略招募的，这些医院每年接生约18万名新生儿，很好地代表了大量未得到充分研究的南美人口。关于产妇保健、生育和行为风险以及可能在这些结果中发挥重要作用的社会经济和人口因素的数据是可用的。将使用卫生生产的卫生经济学模型和先进的多变量技术来研究所有可能相关的投入和特征的贡献。这项研究具有重要意义，因为它提供了对若干南美洲人口不良出生结果负担的可靠评估，确定了卫生政策和干预措施可以针对的风险因素，以改善出生结果，并允许对各种风险因素的影响和作用进行国际比较，这不仅有助于确定所研究国家的预防战略，也有助于确定包括美国在内的其他国家的预防战略。一个例子是将这些高度混合的人群中婴儿和母亲祖先的影响与美国的人群进行比较，在美国，发现低出生体重和早产率因种族而有显著差异。这项研究还为进一步研究相关风险因素和基因变异之间的相互作用提供了关键的初步步骤，这些研究也可能涉及这些结果，并为研究选定干预措施改善出生结果的有效性的临床试验提供了关键的初步步骤。

DESCRIPTION (provided by applicant): Birth weight, gestational age and intrauterine growth (IUG) are important birth outcomes that significantly contribute to future health. Adverse outcomes including low birth weight (LBW), preterm birth and IUG restriction (IUGR) increase substantially the risks of mortality and disability. About 28% of the 4 million neonatal deaths that occur each year worldwide are related to preterm birth, and about 80% occur among LBW infants. LBW and preterm birth are common outcomes and have been on the rise in the past two decades- 16% of babies worldwide are born at LBW. The etiology of these outcomes remains largely unknown but several environmental, behavioral and genetic risks are thought to be involved through both independent and interactive roles. Reliable studies of birth outcomes in South America have been relatively scarce and most previous studies have relied on limited case-control samples as well as fairly simple statistical techniques that are highly vulnerable to bias. This study aims at obtaining reliable estimates of the rates of adverse birth outcomes and identifying health, demographic, behavioral and socioeconomic risk factors that contribute to these outcomes through independent or interactive effects in unique and large birth samples of non-malformed infants from 8 South American countries (more than 100,000 births) recruited through the Latin American Collaborative Study of Congenital Anomalies (ECLAMC). These samples were recruited using the same sampling and data collection strategy in about 90 hospitals that attend about 180,000 births annually and are well representative of large and understudied South American populations. Data is available on maternal health, fertility and behavioral risks as well as on socioeconomic and demographic factors that may play an important role in these outcomes. A health economics model for health production and advanced multivariate techniques will be used to study the contribution of all potentially relevant inputs and characteristics. The study has important implications by providing a reliable assessment of the burden of adverse birth outcomes in several South America populations, identifying risk factors that can be targeted by health policies and interventions to improve birth outcomes and allowing international comparisons of the effects and roles of various risk factors which further help to identify prevention strategies not only in the studied countries but also in other countries including the US. An example would be comparing the effects of infant and maternal ancestry in these highly admixed populations to those in the US where LBW and preterm rates are found to vary significantly by race. The study also provides a key preliminary step to larger studies of interactive effects between relevant risk factors and genetic variants that may also be involved in these outcomes and to clinical trials that study the effectiveness of selected interventions to improve birth outcomes. PUBLIC HEALTH RELEVANCE: This project aims at identifying determinants of adverse birth outcomes including low birth weight, preterm birth and intrauterine growth restriction in several understudied South American populations. Study results are highly relevant for identifying prevention strategies not only for the included countries but also for others including the United States.