There are several causes for lower back pain in early pregnancy, which up to 75% of pregnant women experience. Some of the most common causes are the growing uterus, posture changes, and an increase of hormones. All of these things are normal and will not affect the fetus or the pregnancy. In rare cases, lower back pain can be a symptom of something more serious, such as a kidney infection or sciatica.
The body’s center of gravity changes during pregnancy to accommodate the growing uterus. This usually means a change in posture as the body tries to get comfortable adjusting to a new center of gravity. Adopting a new posture can use back muscles that are not often in use, causing muscle pain in the lower back. Although many women do not experience a large amount of weight gain early in the pregnancy, those that do may be adding to the back pain as extra weight makes muscles and joints work harder than usual.
Hormones play a part in lower back pain as well. Increased hormones tend to loosen joints to make room for the baby and make it physically easier to give birth, but this also loosens up the joint that connects the pelvis to the spine. Aches and pains in the lower back can be an effect of this loosened joint because the pelvis is moving around more than it did before the pregnancy.
In more extreme cases, lower back pain in early pregnancy can be a symptom of sciatica or a kidney infection. Only about 1% of pregnant women suffer from sciatica, which is characterized by leg pain or numbness that can reach all the way down to legs and toes. Kidney infections can be identified by pain under the ribs, especially when accompanied by vomiting, fever or bloody urine.
Most low back pain occurs in the back part of the pelvis or in the lumbar vertebrae of the lower back. Both of these can be aggravated by heavy exercise, twisting, lifting and climbing. To combat pain in early pregnancy, some medical professionals recommend stretching, swimming, and low impact walking. A medical professional should be consulted before a pregnant woman experiencing back pain attempts any of these methods of pain relief. It is also helpful for her to be mindful of proper posture, avoid standing for long periods of time and wear comfortable shoes.