Normally, low antithrombin III in pregnant women is abnormal, and is considered to be related to nephrotic syndrome, severe infections, etc., and needs to be treated according to medical advice. The normal range of antithrombin III is between 258.8 and 310.2mg/L by immuno-rocket electrophoresis. If the low level of this index is found in pregnant women, it is considered to be related to congenital factors, and should also be alerted to liver disease, disseminated intravascular coagulation, nephrotic syndrome, pre-thrombotic state or thrombotic disease, etc. Therefore, it is necessary to cooperate with the doctor actively in the treatment. If pregnant women with low antithrombin III don’t pay attention to it and the condition aggravates, it may cause serious impact on the growth and development of the fetus and their own health. Usually, pregnant women need to combine medical history, symptoms, signs and other auxiliary examination results to diagnose the disease. In clinical practice, it is recommended that pregnant women who have a clear cause of low antithrombin III adjust their mindset, actively cooperate with doctors in treatment, and attend obstetric checkups on time.