The National Standard for Normal Fetal Growth
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 2,802
- 试验地点
- 11
- 主要终点
- Establish a standard for normal fetal growth (velocity) and size for gestational age in the U.S. population.
研究概览
简要总结
Normal fetal growth is a critical component of a healthy pregnancy and the long-term health of the offspring. Pivotal to understanding the dynamics of human fetal growth and to defining normal and abnormal fetal growth is the development of standards for fetal growth. The study's purpose was to establish standards for normal fetal growth and size for gestational age for 4 racial/ethnic groups of pregnant women with the eventual creation of individualized standards for fetal growth and improvements in fetal weight estimation. These data for a contemporary cohort of pregnant women should provide data for clinical management.
详细描述
Summary and aims:
Normal fetal growth is a critical component of a healthy pregnancy and the long-term health of the offspring. Pivotal to understanding the dynamics of human fetal growth and to defining normal and abnormal fetal growth is the development of standards for fetal anthropometric parameters measured longitudinally throughout gestation, which, in turn, can be used to develop interval velocity curves and customized for genetic and physiological factors. We propose to conduct a multi-center prospective observational study (1) to establish a standard for normal fetal growth (velocity) and size for gestational age in the U.S. population; (2) to create an individualized standard for fetal growth potential; and (3) to improve accuracy of fetal weight estimation.
Eligibility:
• Healthy, low-risk pregnant women (both obese and nonobese) between the ages of 18 and 40 from each of the following four self-identified race/ethnicity backgrounds: African American, Asian, Caucasian, and Hispanic.
Design:
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- 未提供
排除标准
- 未提供
结局指标
主要结局
Establish a standard for normal fetal growth (velocity) and size for gestational age in the U.S. population.
时间窗: 3 years
Fetal growth trajectories were created using 2-D ultrasound fetal biometry including biparietal diameter, head circumference, humerus length, abdominal circumference, and femur length using standardized protocols. Estimated fetal weight (EFW) was calculated. Fetal growth trajectories were created using linear mixed models with cubic splines for estimating racial/ethnic specific fetal growth curves for size, methods that accounted for the variation across individual fetuses. For EFW and each individual anthropometric parameter, we tested for overall differences in the racial/ethnic-specific curves using a likelihood-ratio test. When the global test was significant (\<.05 level), we tested for week-specific differences by race/ethnicity using Wald tests at each week of gestation. These tests were conducted on the estimated curves with and without adjustment for maternal characteristics. A fetal growth velocity standard by maternal race/ethnicity was also created.
Create an individualized standard for fetal growth potential.
Individualized and customized fetal growth models will be created using two- dimensional ultrasound measures. Individualized or customized definitions of small for gestational age or large for gestational age will be compared to the NICHD Fetal Growth Study singleton standard cut-points of 10th and 90th percentiles, respectively, to see if they improve detection of maternal and neonatal health outcomes.
Improve accuracy of fetal weight estimation.
Since the last ultrasound exam is scheduled at term, it was expected that many women would deliver within 3 days after the last ultrasound exam. A formula (or formulas) to estimate fetal weight will be created using a multiple linear regression to include not only the 2-D and 3-D sonographic measurements but also factors such as maternal height and weight, sex of the fetus, and glucose challenge test result. We will identify a formula that provides the best estimate of fetal weight, and apply that formula to a validation group. If the sample size allows, we will randomly split the whole cohort into two groups: one group for testing and the other for validation. If the statistical power is insufficient for splitting, we will use cross-validation.
次要结局
- Construct an individualized standard for fundal height.
- Collect blood samples for an etiology study of gestational diabetes and a prediction study of fetal growth restriction and/or overgrowth.
- Collect placental tissues and cord blood in selected cases and controls for studies on the etiology of idiopathic fetal growth restriction.
- Collect dietary intake data to study the association between nutrition and fetal growth.