Pregnant women appear left leg numbness mainly consider the following reasons: 1, lumbar disc herniation, because pregnant women in mid-pregnancy with the increase of the abdomen, will accelerate the lumbar disc herniation, will cause sciatic nerve compression. After the sciatic nerve compression, the patient will have numbness of the left leg, mainly to the lateral calf numbness, and some patients will also have a feeling of soreness and swelling of the buttocks. 2, if the patient is to the numbness of the left upper leg or there is a sensory loss of the main, consider that after the pregnancy due to the increase of the abdomen, the increasing uterus compression of the lateral femoral cutaneous nerve. Numbness of the upper left leg can occur, but also mainly to the outer thigh of the numbness of the main, so pregnant women only left leg numbness, the main consideration of the above two aspects of the reason.