During human development, which statement is correct regarding primary hematopoiesis location(s)? 1) fetal liver/spleen; 2) yolk sac; 3) bone marrow. The spleen is the active site of hematopoiesis in childern. 1) yolk sac; 2) fetal liver/spleen; 3) fetal bone marrow. The active site of hematopoiesis in adults is the liver. 1) fetal bone marrow; 2) yolk sac; 3) fetal liver/spleen. A serious developmental disorder associated with multiple -thalassemia ( -globin) genetic defects is immune problems in men. bleeding disorders in women. hydrops fetalis and a high risks of intrauterine fetal death. elevated mean corpuscular volumen (MCV). elevated \% hematocrit (PCV) levels. .