A fetus that does not grow beyond the 10th percentile of conventionally accepted weight for gestational age. The disease is fetal growth restriction (MONDO_0005030, a Monarch Disease Ontology id). Also known as: IUGR, fetal Growth retardation, fetal SGA, fetal growth retardation, fetal small for gestational Age, fetus small for gestational Age, foetal Growth retardation, foetal SGA.