A level 2 ultrasound is a more detailed ultrasound to evaluate the anatomy of the feus more comprehensively. Some practictioners use the term "level 3" ultrasound to mean an even more detailed study, but there is no standard usage for the term: it may or may not involve using 3-D techniques depending upon who does the ultrasound.
Ultrasound detection of anemia (low amount of red blood cells) in the fetus usually involves measuring the speed of blood flow through various blood vessels. A higher speed of flow means a lower amount of red blood cells (less "resistance" to flow within the blood vessel).
If anemia is strongly suspected, the mother should discuss with her physician possible causes of anemia in the fetus and whether any further or continuing evaluation is necessary.
i had a friend who posted and said that her ob told her that the baby looked fine but saw a blood drop in the embryo..and would need a level 3 ultra sound? we have never heard of this, and is a level 3 a 3d ultrasound?
I do not really understand your question: could you provide some more information?