Megaloblastic anaemia is also called nutritional megaloblastic anemia. Megaloblastic anemia complicating pregnancy is a macrocytic anemia caused by a lack of folic acid and/or vitamin B12, with megaloblastic series appearing in the bone marrow. It is relatively rare in clinical practice, accounting for 7% to 8% of all anemias. It occurs all over the world, and in China it mostly occurs in northern regions such as Shanxi and Shaanxi, with malnutrition as the main cause. It not only affects hematopoiesis, but also involves the nervous, digestive, circulatory, immune and endocrine systems, manifesting as a systemic disease. Megaloblastic anemia complicating pregnancy is relatively common, accounting for 43.2% of all megaloblastic anemias.