Fetal growth restriction (FGR) as a common pregnancy complication is generally defined as the failure of a fetus to achieve its genetically determined full growth potential due to placental dysfunction. Early-onset (<32. gestational week) FGR is associated strongly with abnormal trophoblastic invasion and consequent placental insufficiency. Conditions leading to FGR are the disorders inherent to the fetal-placental-maternal unit, fetal malnutrition, resulting in a significantly increased risk of stillbirth, neonatal morbidity, neonatal death, and long-term adverse outcome. Once the fetal size, typically using estimated fetal weight and/or abdominal circumference below the tenth percentile compared to gestational age reference standards, multimodality assessment (including Doppler velocimetry in umbilical, and middle cerebral arteries, CTG and biophysical profile) is recommended. At present, the most recognized criteria to define early and late FGR are those derived from an international Delphi survey consensus. Early diagnosis, close follow-up and timely delivery of pregnancies with FGR are of crucial importance for perinatal short- and long-term outcome. The main distinction between small for gestational age (SGA) and growth-restricted fetus is that the healthy SGA fetus may be small but not at increased risk of adverse perinatal outcome. Orv Hetil. 2025; 166(9): 331–340.