Hi, Thanks for the query. Some amount of backache can be seen in advanced pregnancy. Simple backache will get relieved by local analgesics and rest. If the pain persists even after taking analgesics, better to consult gynecologist once and get examined to rule out the possibility of preterm labor. Usually in multigravida head engagement will be delayed and can occur at the time of onset of labor pains. So, as your baby s head is getting engaged, once check for cervical changes. By examination doctor can access the cervical changes and find out the possibility of preterm labor. If there are no cervical changes, analgesics can help in relieving the pain. Take care.