Causes of Lower Back Pain in Pregnancy

Lower back pain in pregnancy is very common. It is estimated that as many as 50% women will develop some kind of back pain during pregnancy. The pain comes from a variety of structures including sacroiliac joints, lower back structures and sometimes the sciatic nerve.There are a few different reasons why you might get lower back pain in pregnancy.

Big hormone changes are taking place

In order to give birth and let a relatively large object (baby) through the narrow pelvic canal the pelvic bones have to be able to move and widen. To enable this the body releases a hormone called relaxin which causes the bodies ligaments to soften and relax. This affects the whole body including the lower back but it especially affects the sacroiliac joints. The sacroiliac joints are supported by large, tough ligaments and these ligaments must soften to allow delivery.

The pelvis and sacroiliac joints - back	Front

This is what you need when you are giving birth but the effects are not so good both before and after birth as the large, strong ligaments supporting your back and sacroiliac joints are not so supportive.

To make matters worse if you had poor muscle tone, so less supportive core stability muscles, or a history of back pain before getting pregnant its more likely that you will get back pain in pregnancy.

During pregnancy a lot of weight is gained - and it’s mostly at the front

This means that your posture has to rapidly adapt to compensate for this. This happens by increasing the hollow or the lordosis in the small of your back. lower back pain in pregnancy

I saw a news item hit the headlines recently which looked at the difference between male and female spines and discussed how women’s spines have adapted to cope with these changes in order to reduce lower back pain in pregnancy (1)

Changes in the blood supply to the muscles and joints make them more vulnerable and so repetitive lifting or bending during pregnancy may worsen your lower back pain problem.

The other important thing to consider is that women who are pregnant can get all the regular types of back pain too and that it may not be related to pregnancy at all. This section on the cause of lower back pain outlines the different types of back problem all of us have to deal with.

Lower Back Pain Toolkit Home Page

Pregnancy Back Pain Overview

Treatment of Lower Back Pain during Pregnancy

Back Pain in Early Pregnancy

Back Pain in Pregnancy - Sacroiliac Joint Dysfunction

Sacroiliac Joint Dysfunction