The National Standard for Normal Fetal Growth

正常的胎儿生长是人类发育的一个重要方面，并对整个生命周期产生影响。 目前，胎儿生长的临床评估标准很少，特别是种族/民族特异性。 作为回应，流行病学、统计学和预防研究部设计了NICHD胎儿生长研究，其目的有三个：（1）建立低风险婴儿正常胎儿生长（速度）和胎龄大小的国家标准;（2）建立最佳胎儿生长的个性化标准;（3）提高临床胎儿体重估计的准确性。 这项研究将从12个参与的临床中心招募2,400名健康、非肥胖、低风险的孕妇。 大约600名女性将分别来自以下自我认定的种族/民族背景：非裔美国人、亚洲人、高加索人和西班牙裔。妇女将在怀孕的头三个月被招募，并在怀孕期间进行随访。 此外，还将招募600名肥胖女性。 女性将随机接受妊娠特异性2D和3D超声检查。 将在每次临床访视时以及分娩时收集妇女的数据，以确定饮食、身体活动和健康信息。 还对孕妇和婴儿进行人体测量评估，以评估身体成分。 2012年2月，实施了一项后续方案，纳入了350对双胞胎。 本研究的目的是建立一个当代成长轨迹的双胞胎，并比较它与单胞胎。 考虑到双胞胎在当代出生队列中的流行，这些信息对临床医生来说至关重要。

Normal fetal growth is a critical aspect underlying human development and has implications across the lifespan. Currently, few standards exists for the clinical assessment of fetal growth, particularly race/ethnic specific. In response, the Division of Epidemiology, Statistics & Prevention Research designed the NICHD Fetal Growth Study whose aims are threefold: (1) establish a national standard for normal fetal growth (velocity) and size for gestational age among low risk infants; (2) create an individualized standard for optimal fetal growth; and (3) improve the accuracy of clinical fetal weight estimation. This study will recruit 2,400 healthy, non-obese, low risk pregnant women from 12 participating clinical centers. Approximately 600 women each will come from the following self-identified race/ethnicity background: African American, Asian, Caucasian, and Hispanics. Women will be recruited in the first trimester and followed up through pregnancy. In addition, 600 obese women will also be recruited. Women will be randomized to receive gestation-specific 2D and 3D ultrasounds. Data will be collected from women at each clinical visit to ascertain diet, physical activity and health information and also at delivery. Anthropometric assessment of the pregnant women and baby also are conducted to assess body composition. An February 2012, a follow on protocol was implemented to include 350 dichorionic twins. The aim of this study is to establish a contemporary growth trajectory for twins, and to compare it with that of singletons. This information is critical fr the clinicians, given the epidemic of twin births in contemporary birth cohorts.