Typical fetal growth is a critical component for a healthy pregnancy and for ensuring the health and well-being of infants throughout childhood and adolescence. Pivotal to understanding the dynamics of human fetal growth and to defining typical and atypical fetal growth is the development of standards for fetal anthropometric parameters, measured longitudinally throughout gestation. Such measures can be used to develop interval velocity curves and customized to assess etiologic determinants such as genetic and physiological factors. Check the "Press Releases and Study Tools" section to find out how the study put these measures into practice.
The NICHD Fetal Growth Studies is an ambitious observational epidemiologic study that recruited 2,334 low risk pregnant women from 12 U.S. clinical sites, 2009-2013:
- Columbia University
- Christiana Care Health System
- Saint Peters University Hospital
- New York Hospital, Queens
- Medical University of South Carolina
- University of Alabama
- Northwestern University
- University of California, Irvine
- Long Beach Memorial Medical Center
- Fountain Valley Hospital
- Women and Infants Hospital of Rhode Island
- Tufts University
In addition, two other cohorts were recruited: 1) a cohort comprising 468 pregnant women with obesity, and 2) a twin cohort comprising 171 women with dichorionic twin pregnancies. Study participants underwent five ultrasounds (2D and 3D imaging) during pregnancy at a priori defined gestational ages. Nutritional and anthropometric assessments were performed during clinical visits followed by the collection of blood specimens.
Singleton Cohort
The primary goal of this study was to establish a standard for typical fetal growth (velocity) and size for gestational age in the U.S. population. Additional goals were to create an individualized standard for fetal growth potential and to improve accuracy of fetal weight estimation.
Fetal Growth-Gestational Diabetes Mellitus Study
Designed within this cohort is a prospective study of longitudinal risk factors of gestational diabetes mellitus (GDM) and a nested case control study of a comprehensive panel of biomarkers including metabolomics profiles focusing on the etiology and prediction of GDM and its implications for fetal growth.
Dichorionic Twin Cohort
Twin gestations represented 3.4% of U.S. births in 2013, yet there was limited contemporary data on the estimation of fetal growth trajectories in twins. The NICHD Fetal Growth Studies enrolled 171 dichorionic twin pregnancies. The primary objective was to empirically define the trajectory of fetal growth in dichorionic twins using longitudinal two-dimensional ultrasonography and to compare the fetal growth trajectories for dichorionic twins with those based on a growth standard developed by our group for singletons.
Genetics of Fetal Growth in Diverse Ancestral Populations
Despite strong influence of genetics on fetal growth, the specific genetic loci involved at different stages of gestation are not clearly known. Furthermore, fetal growth displays significant differences among global regions and ethnic populations, but what underlies this remains puzzling because established maternal and fetal non-genetic determinants of fetal growth explained only a very small fraction of these disparities. Therefore, using genome-wide data from the entire NICHD Fetal Growth Studies cohort, we seek to identify genetic variants that influence fetal growth and related maternal traits among different ancestral populations (PI: Fasil Tekola-Ayele). Specifically, we aim to: 1) identify genetic loci associated with various measures of fetal growth and related maternal cardiometabolic traits at different stages of gestation, 2) determine the influence of interactions between genetic variants and maternal cardiometabolic and socio-demographic factors on fetal growth, and 3) determine the contribution of genetic ancestry to observed disparities in fetal growth among different ancestral groups. Knowledge gained from the project is anticipated to illuminate genetic mechanisms in longitudinal fetal growth variations and the role of genetic ancestry for observed disparities in fetal growth among different ancestral populations.
Principal Investigator
Division Collaborators
- Una Grewal, Ph.D., M.P.H.
- Aiyi Liu, Ph.D.
- Rajeshwari Sundaram, M.Stat., Ph.D.
- Fasil Tekola Ayele, Ph.D.
Press Releases and Study Tools
- Estimated Fetal Weight Growth Velocity Calculator. June 2020.
- Estimated Fetal Weight Calculator. February 2020.
- NIH study explores link between maternal obesity and fetal growth during pregnancy. December 10, 2018.
- Blood test may identify gestational diabetes risk in first trimester, NIH analysis suggests. August 16, 2018.
- High thyroid hormone level in early pregnancy linked to gestational diabetes, NIH study finds. June 7, 2018.
- More than one day of early-pregnancy bleeding linked to lower birthweight. May 9, 2018.
- Obesity during pregnancy may lead directly to fetal overgrowth, NIH study suggests. November 13, 2017.
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