The anomaly scan, also sometimes called the anatomy scan, 20 week ultrasound, or level 2 ultrasound, is a pregnancy ultrasound performed between 18–22 weeks of gestational age. This ultrasound is performed as a matter of routine prenatal care, to measure the fetus so that growth abnormalities can be recognized quickly later in pregnancy, and to assess for congenital malformations and multiple pregnancies.
A standard anatomy scan typically includes
1) Fetal number, including number of amnionic sacs and chorionic sacs for multiple gestations
2) Fetal cardiac activity
3) Fetal position relative to the uterus and cervix
4) Location and appearance of the placenta, including site of umbilical cord insertion when possible
4) Amnionic fluid volume
5) Gestational age assessment
6) Fetal weight estimation
7) Fetal anatomical survey
8) Evaluation of the maternal uterus, tubes, ovaries, and surrounding structures when appropriate
