Abnormal Fetal Growth: Small for Gestational Age, Fetal Growth Restriction, Large for Gestational Age: Definitions and Epidemiology

Obstet Gynecol Clin North Am. 2021 Jun;48(2):267-279. doi: 10.1016/j.ogc.2021.02.002.

Abstract

Abnormal fetal growth (growth restriction and overgrowth) is associated with perinatal morbidity, mortality, and lifelong risks to health. To describe abnormal growth, "small for gestational age" and "large for gestational age" are commonly used terms. However, both are statistical definitions of fetal size below or above a certain threshold related to a reference population, rather than referring to an abnormal condition. Fetuses can be constitutionally small or large and thus healthy, whereas fetuses with seemingly normal size can be growth restricted or overgrown. Although golden standards to detect abnormal growth are lacking, understanding of both pathologic conditions has improved significantly.

Keywords: Fetal growth restriction; Fetal overgrowth; Intrauterine growth restriction; Large for gestational age; Macrosomia; Placental insufficiency; Small for gestational age.

Publication types

  • Review

MeSH terms

  • Female
  • Fetal Development*
  • Fetal Growth Retardation / diagnostic imaging
  • Fetal Growth Retardation / epidemiology*
  • Fetal Macrosomia / diagnostic imaging
  • Fetal Macrosomia / epidemiology*
  • Fetus / diagnostic imaging
  • Gestational Age
  • Humans
  • Infant, Newborn
  • Infant, Small for Gestational Age*
  • Placenta / diagnostic imaging
  • Placental Insufficiency / diagnostic imaging
  • Placental Insufficiency / epidemiology
  • Pregnancy
  • Ultrasonography, Doppler / methods
  • Ultrasonography, Prenatal / methods
  • Umbilical Arteries / diagnostic imaging