When a pregnant woman feels numbness in her arms at night, it is caused by poor blood circulation due to pressure on the arms while sleeping in the side position. In this case, try to pay attention to put the arm flat or on one side, do not press, can reduce the numbness caused by poor blood circulation. When numbness occurs, you can pat your arm gently to promote blood circulation, or gently massage it to improve the numbness. You should also pay attention to the fact that you should keep your arms warm when you sleep and try not to let them get cold. If the arm gets cold, it can easily lead to capillary spasms, convulsions and contractions, which can cause numbness. Calcium should be supplemented in the right amount, if lack of calcium, it will easily cause numbness in the arms, leg cramps and back pain.