Low albumin in pregnant women is usually caused by malnutrition, liver disease, kidney disease and hypertension during pregnancy. 1. Malnutrition: With the growth and development of the fetus after pregnancy, the requirement of nutrients will increase. If the nutritional intake of pregnant women is insufficient, it may lead to malnutrition and thus low albumin. 2. Liver disease: Since albumin is mainly synthesized by the liver, if there is acute or chronic liver disease during pregnancy, it will lead to insufficient albumin synthesis, so low albumin occurs. 3. Kidney disease: If pregnant women suffer from kidney disease, such as nephritis, abnormal kidney development, etc., it will lead to the loss of albumin in pregnant women’s body, thus leading to low albumin. 4. Hypertension during pregnancy: it is a common cause, if pregnant women have high blood pressure during pregnancy, it will also increase the loss of protein and cause low albumin. If a pregnant woman has low albumin, she should go to the hospital in time for examination and ask the doctor to make a clear diagnosis and treatment.