Defining normal and abnormal fetal growth: promises and challenges

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ajog.2009.10.889 Byline: Jun Zhang (a), Mario Merialdi (b), Lawrence D. Platt (c), Michael S. Kramer (d) Keywords: biomarker; definition; Doppler; fetal growth; restriction; standard Abstract: Normal fetal growth is a critical component of a healthy pregnancy and influences the long-term health of the offspring. However, defining normal and abnormal fetal growth has been a long-standing challenge in clinical practice and research. We review various references and standards that are used widely to evaluate fetal growth and discuss common pitfalls of current definitions of abnormal fetal growth. Pros and cons of different approaches to customize fetal growth standards are described. We further discuss recent advances toward an integrated definition for fetal growth restriction. Such a definition may incorporate fetal size with the status of placental health that is measured by maternal and fetal Doppler velocimetry and biomarkers, biophysical findings, and genetics. Although the concept of an integrated definition appears promising, further development and testing are required. An improved definition of abnormal fetal growth should benefit both research and clinical practice. Author Affiliation: (a) Epidemiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD (b) Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland (c) Center for Fetal Medicine and Women's Ultrasound, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA (d) Departments of Pediatrics and of Epidemiology and Biostatistics, McGill University Faculty of Medicine, Montreal, Quebec, Canada Article History: Received 18 March 2009; Revised 6 July 2009; Accepted 29 October 2009 Article Note: (footnote) Reprints not available from the authors., This study was supported in part by the Intramural Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (J.Z.)., The views expressed in this document are solely the responsibility of the authors and do not necessarily represent the views of the National Institutes of Health or the World Health Organization.