Fetal Anomaly, also known as birth defect or congenital anomaly, refers to abnormal or unexpected structural and functional changes to one or more parts of the fetal body that occur during prenatal development. Structural anomalies impact the formation of part of the body, such as the heart, lungs, kidneys, limbs, and craniofacial features. Functional anomalies impact how a part or system of the body operate, such as the brain, nervous system, skeletal system, and sensory system. Fetal anomalies are typically diagnosed between 18 and 23 weeks of pregnancy during routine prenatal testing. Not all fetal anomalies require treatment or are fatal, but fetal anomalies do increase the risk of intrauterine fetal demise (stillbirth), death in the neonatal period, and long-term, life-limiting complications.