Feeling numbness of the mouth at 29 weeks of pregnancy may be a physiological phenomenon caused by compression, or it may be caused by electrolyte disorders, facial neuritis and other diseases. 1. Physiological phenomenon: when the patient sleeps in an inappropriate position or rests on his back for too long, it may lead to poor blood circulation around the face due to compression, and then the physiological phenomenon of numbness of the mouth. 2. Disease factors: (1) electrolyte disorders: after pregnancy by the body’s hormone levels, may make the gastrointestinal tract dysfunction, resulting in patients with inappropriate absorption and thus lead to electrolyte disorders. Electrolyte disorders are prone to tingling of the hands and mouth and numbness of the fingertips and other symptoms. (2) Facial neuritis: Facial neuritis occurs due to the stimulation of inflammatory factors, usually causes damage to the face and regional peripheral nerve tissues, resulting in slow nerve function and numbness, which leads to numbness in the patient’s mouth. To summarize, the causes of numbness in 29 weeks of pregnancy are different, and it is recommended that patients go to the hospital in time for examination in order to clarify the specific causes of the disease.