Causes of Back Pain in Pregnancy
Pelvic (sacroiliac joint dysfunction) and 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. That is a lot of women with back pain!
There are several reasons why pregnant women get lower back pain.
- Hormones.
This is a really important point. 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. It does this by releasing a hormone called relaxin which causes the ligaments to soften and relax. This especially affects the sacroiliac joints.
The pelvis from the back

The pelvis from the front

This is great when you are giving birth but not so good both before and after as the large strong ligaments supporting your back and sacroiliac joint are not so rigid.
If you had poor muscle tone 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.
A recent news item hit the headlines last month 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.
- Changes in the blood supply to the muscles and joints make them more vulnerable.
- Repetitive lifting or bending during this time may worsen the problem.
The other important thing to consider is that women who are pregnant can get all the regular types of back pain 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.
Lower Back Pain Toolkit Home Page
Treatment of Lower Back Pain during Pregnancy
Back Pain in Pregnancy - Sacroiliac Joint Dysfunction
18-Feb-2008


