what is an anatomy scan

An anatomy scan, also known as an anomaly scan, 20-week ultrasound, or level 2 ultrasound, is a prenatal ultrasound that evaluates the anatomic structures of the fetus, placenta, and maternal pelvic organs. This scan is an important and common component of routine prenatal care, and it is usually conducted between 18 and 22 weeks gestation, but most often performed at 19 weeks. Prior to 18 weeks gestation, the fetal organs may be of insufficient size and development to allow for ultrasound evaluation, and scans performed beyond 22 weeks gestation may limit the ability to seek pregnancy termination, depending on local legislation. The function of the ultrasound is to measure the fetus so that growth abnormalities can be recognized quickly later in pregnancy, to assess for congenital malformations and multiple pregnancies, and to plan the method of delivery. During the scan, the sonographer will take many measurements of the fetus, including the fetal number, fetal cardiac activity, fetal position relative to the uterus and cervix, location and appearance of the placenta, amniotic fluid volume, gestational age assessment, fetal weight estimation, fetal anatomical survey, and evaluation of the maternal uterus, tubes, and other organs. The sonographer will also look for specific conditions or abnormalities, such as congenital disabilities or structural issues with certain organs. The 20-week anatomy scan is not harmful, and studies have shown that ultrasound is not dangerous to the mother or the fetus. In most cases, the scan is a positive experience, and the healthcare provider will not find any major anomalies.