Pregnant women with left leg numbness mainly consider the following causes: 1, lumbar disc herniation, because pregnant women in the middle of pregnancy with the increase in abdomen, will accelerate the lumbar disc herniation, will cause the sciatic nerve compression. After the sciatic nerve is compressed, the patient will experience numbness in the left leg, mainly in the lateral calf, and some patients will also experience soreness and swelling in the buttocks. 2, if the patient is mainly numbness in the upper left leg or has hyperalgesia, consider that after pregnancy, due to the increase in the abdomen, the enlarged uterus compresses the lateral femoral cutaneous nerve. The numbness of the upper left leg can appear, also mainly the numbness of the outer thigh, so pregnant women only have numbness in the left leg, mainly consider the above two causes.