has part has part characteristic of has modifier embryo development Growth delay Intrauterine growth retardation Intrauterine growth restriction is a newer term that is preferred over Intrauterine growth retardation. The causes of IUGR include maternal abnormalities (chronic hypertension, cyanotic heart disease, smoking, drug abuse), placental or umbilical cord abnormalities (including placenta previa and cord anomalies), maternal medicationas, and genetic disorders of the fetus. abnormal decreased rate