Second trimester detailed or targeted anatomical survey (level III ultrasound)
This ultrasound is incredibly detailed and is designed to assess all appreciable fetal structures at 18-20 weeks gestation. At this point in the pregnancy, details of the fetal organ systems (skeletal, cardiovascular, genitourinary, gastrointestinal, etc) can be sonographically imaged. Many structural or genetic concerns can be identified at this stage in the pregnancy. There are some structures (ex. The fetal brain), however, which are in constant development and cannot be fully assessed in one visit and may need to be imaged over a series of ultrasounds, especially if there is a concerning finding.