As your uterus expands, you may feel aches and pains in the back, abdomen, groin area, and thighs.
Many women also have backaches and aching near the pelvic bone due to the pressure of the baby's head, increased weight, and loosening joints. The discomfort can be felt across the lower back, the buttocks and down the legs. Backache is exacerbated if you stand for too long with poor posture or you lift heavy objects. This is especially true during the third trimester.
Some pregnant women complain of pain that runs from the lower back, down the back of one leg, to the knee or foot. This is called sciatica. It is thought to occur when the uterus puts pressure on the sciatic nerve.
Some women may feel intense pain in their lower back when they rotate the spine and pelvis in opposite directions. For example, this can happen when you turn sideways in bed.
During pregnancy, your progesterone levels rise. This higher level of progesterone softens the ligaments of the pelvic bone in preparation for the stretching that will occur during labor. This softening also applies to the ligaments in the spine, which puts extra strain on the back and hip joints.
If you feel the intense pain in your lower back when turning sideways, this is caused by your baby resting against your sacroiliac joint. This joint is about 3 inches in from the top of your buttocks. When you move sideways, this joint opens and closes causing the pain.
To alleviate body aches, try the following:
If you experience pain caused by your sacroiliac joint, you may want to try osteopathy, which involves manipulation of the bones and muscles. This pain may also go away by the 5th month if you can wait that long.
Call the doctor if pain does not get better, but there is generally no risk to the baby.