In the second trimester of pregnancy, back pain, if it is excluded that it is due to a lack of calcium, will be delivered very soon. This is very common in the second trimester of pregnancy and may be caused by a lack of calcium, or it may be a sign that labor is imminent. This is because in the second trimester, with the rapid development of the fetus, it is easy for pregnant women to be deficient in all kinds of nutrients and minerals, especially calcium, iron, vitamins, etc. Once deficient, it is easy to cause back pain. Once deficient, it is easy to cause the symptoms of lumbago and back pain. Low back pain is accompanied by a history of leg cramps. In addition to quickly replenish vitamin B12 and calcium, but also timely consultation with the doctor to seek professional help, the lack of a slight person is recommended to dietary supplements. And in the late stages of pregnancy, with the further development of the fetus, the gestational week is further close to the expected date of delivery, the fetus gradually into the pelvis, can also lead to the emergence of back pain and other phenomena. On the other hand, it should also be noted that some pregnant women have contractions that manifest as regular back pain. So it may also be a symptom of approaching labor.