Trends in C-Section and Induction Use among US Births and Consequences for US Birth Weight

美国新生儿剖腹产和引产的趋势及其对美国出生体重的影响

• 批准号: 9807952
• 负责人: Ryan Kelly Masters
• 金额: $ 7.08万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-05 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9807952
• 关键词: Affect; Age Distribution; Attention; Birth; Birth Weight; Cesarean section; Demography; Discipline of obstetrics; Ethnic Origin; Event; Fetal Growth; Gestational Age; Incidence; Induced Labor; Infant; Intervention; Joints; Latina; Length; Life Tables; Link; Low Birth Weight Infant; Methods; Modeling; Mothers; Not Hispanic or Latino; Outcome; Policies; Population; Pregnancy; Probability; Process; Public Health; Race; Recommendation; Reporting; Research; Research Personnel; Source; System; Techniques; Term Birth; Time; United States; Vagina; Variant; Vital Statistics; Woman; World Health Organization; conditioning; ethnic difference; experience; novel; rate of change; simulation; social; trend

Project Summary Average birth weights in the United States declined substantially during the 1990s and 2000s and have not recovered to the birth weight levels prior to the declines. This project documents state-level birth weight trends among U.S. infants born to non-Hispanic black, non-Hispanic white, and Latina women between 1990 and 2014. The project investigates the extent to which increased rates of cesarean section deliveries (C-sections) and labor inductions were responsible for recent changes in U.S. birth weights. Existing research has thus far reported no link between birth weight declines in the United States and the increased use of C-sections and inductions. Futher, existing evidence suggests that changes in U.S. birth weight distributions have occurred across all weeks of gestational age. The anomalous declines in U.S. birth weights are therefore suspected to reflect sources of reduced fetal growth that have been independent of gestational age. However, analytic approaches from extant research have overlooked how the composition of births at gestational ages have changed as a result of rising use of C-sections and inductions. Increased uses of C-sections and inductions have not been random. Rather, they have disproportionately occurred at select gestational ages, which have dramatically shifted when U.S. births take place and how. These labor interventions often affect pregnancies that likely would have resulted in births taking place at older gestational ages and at higher birth weights if the interventions did not occur. The consequences of these changes have altered both the distribution of U.S. births across gestational ages as well as the birth weight distributions of these births. This project will explore how these compositional changes may be responsible for declines in birth weight among infants born to U.S. non-Hispanic black, non-Hispanic white, and Latina mothers in all states between 1990 and 2014. The project will analyze gestational age distributions and birth weight distributions in official National Vital Statistics Systems Natality files for years 1990, 1996, 2002, 2008, and 2014. Traditional demographic techniques and survival models will be used to estimate changes in the joint probabilities of births occurring at specific gestational ages via specific birthing methods (i.e., C-section, induction, or vaginal without intervention). Simulation techniques will be used to illustrate how birthweight distributions among non-Hispanic black, non- Hispanic white, and Latina women in all U.S. States would have changed if rates of C-section use and rates of induced labor had remained constant over the years. The analytic approach of the project is novel and goes well-beyond existing analyses by paying special attention to compositional changes in U.S. births in terms of birth method, birth timing, and birth weight. Findings from the project will contribute significantly to research in demography and public health, and potentially inform obstetric practices and policies.

项目摘要 美国的平均出生体重在20世纪90年代和21世纪初大幅下降， 恢复到下降前的出生体重水平。该项目记录了国家一级的出生体重趋势 在1990年至1999年期间，非西班牙裔黑人、非西班牙裔白色和拉丁裔妇女所生的美国婴儿中， 2014.该项目调查剖宫产率增加的程度（剖腹产） 和引产是造成美国新生儿体重最近变化的原因。现有的研究表明， 报告称，美国出生体重下降与剖腹产使用增加之间没有联系， 诱导。此外，现有证据表明，美国出生体重分布发生了变化， 在所有胎龄的周数中。因此，人们怀疑美国出生体重的异常下降 反映了与胎龄无关的胎儿生长减少的来源。然而，分析 现有研究的方法忽略了胎龄出生的组成如何影响婴儿的出生率。 由于剖腹产和引产的使用越来越多，剖腹产和引产的使用增加 并不是随机的相反，它们不成比例地发生在特定的孕龄， 在美国出生的时间和方式发生了巨大的变化。这些分娩干预往往会影响怀孕 这可能会导致出生在更大的胎龄和更高的出生体重，如果 没有进行干预。这些变化的后果改变了美国的分布。 不同胎龄的新生儿以及这些新生儿的出生体重分布。该项目将探索 这些成分的变化如何导致美国出生的婴儿出生体重下降。 非西班牙裔黑人，非西班牙裔白色和拉丁裔母亲在1990年至2014年之间的所有州。项目 将分析官方国家生命统计中的胎龄分布和出生体重分布 1990、1996、2002、2008和2014年的系统出生率文件。传统的人口统计技术和 生存模型将被用来估计在特定的时间点出生的联合概率的变化。 通过特定的分娩方法确定胎龄（即，剖腹产、引产或阴道无干预）。 模拟技术将被用来说明如何出生体重分布之间的非西班牙裔黑人， 如果剖腹产的使用率和剖腹产的死亡率增加，那么美国所有州的西班牙裔白色和拉丁裔妇女都会改变。 引产多年来一直保持不变。该项目的分析方法是新颖的， 通过特别关注美国出生人口的组成变化， 出生方式、出生时间和出生体重。该项目的研究结果将大大有助于 人口统计学和公共卫生，并可能为产科实践和政策提供信息。