
Sacroiliac Joints are where the pelvic
bones meet the sacrum or tail bone
The sacroiliac joints are where the pelvis attaches to the sacrum, the joints normally have only a tiny amount of movement.
It is very common for pregnant women to develop sacroiliac joint pain.
This is caused by a disruption of the sacroiliac joint due to the hormonal and mechanical changes associated with pregnancy.
If the joints stayed stiff it would create a major problem during childbirth as there would not be enough room for the baby to be delivered.
In order to allow the baby room the body produces a hormone which allows the very stiff ligaments supporting these joints to soften.
This hormone enables an outward, opening up movement of the pelvis. So during pregnancy normally stiff joints become more flexible and this combined with the weight of a developing baby and with changes in posture lead to a high chance of back pain in pregnancy.
Knowing that there is a good chance of developing this type of pain it is a really good idea to try and avoid activities which may aggravate the problem.
Sacroiliac joint problems are made worse with activities that involve using one leg. (This may seem odd but single leg or unilateral activities stress the joint). Examples of this include getting in and out of the car and climbing stairs etc.
Lying down can be very uncomfortable and can lead to back pain during pregnancy. Finding a comfortable position is essential and can sometimes be achieved by lying on your side and using pillows under the tummy for support.
Lying with the legs supported by pillows (see below) may be good to try in the early stages of pregnancy but should be avoided in later stages as the pressure of the baby resting on major blood vessels in this position may be harmful.
Sleeping using a *Full Body Pillow may help you keep your knees together more comfortably at night.

To avoid straining the joints it is a good idea to:

Similar principles apply here as they would for the general, non-pregnant population. Ensure you maintain a correct sitting posture and use a lumbar roll to support the lower back when sitting.
Up to 50% of women will experience pelvic girdle pain or lower back pain during pregnancy. Treatment to help you with your pregnancy back pain often includes advice and information about posture when pregnant and exercises to help strengthen the core or abdominal muscles. Commonly pelvic girdle braces or supports are often suggested too.
These are the two most common types of supports used to help reduce lower back pain during pregnancy. This type on the left supports the lower back and the one on the right is helpful for pelvic girdle pain and sacroiliac joint pain in pregnancy.
| Lower Back Support | Pelvic Girdle and Sacroiliac joint support |
|---|---|
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Some research trials have found that using a sacroiliac brace is useful for reducing this type of back pain (Kaluset al. 2008).The support belt the researchers found helpful was the Bellybra although there are many similar ones on the market.
They looked at a largish (115) group of pregnant women between 20 and 36 weeks of pregnancy with lower back or sacroiliac pain. They compared two different types of pelvic support.
The authors found that both types of support were helpful at reducing lower back pain during pregnancy and that the women using them felt less pain.
The group in the bellybra group did a little better than the tubigrip group. They had less back pain when sleeping, getting up from a sitting position and walking than the tubigrip group.
Another more recent review (Ho et al 2009) has looked the use of pelvic supports in pregnancy and didn't find enough conclusive evidence that they work. However, this paper did say that there was some promising findings around potentially helpful stability changes when the belts were used that needed more investigation.
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The same study by Ho et al (2009) reported the main side effects experienced by some mothers as increased pain, fetal heart rate changes, skin irritation and discomfort.
This is difficult to answer for certain as there is so much variability between pregnant women. I do know that my women's health colleagues often issue tubigrip and sacroiliac joint supports to the mums they see with lower back pain during pregnancy.
I would discuss it with your midwife or physiotherapist and ask them to help you to decide if this is right for you and to help you select the correct support for you. You will need to decide if you need more lower back support or more sacroiliac joint support.
Pennick, V. & Young, G. Interventions for preventing and treating pelvic and back pain in pregnancy. (2008).
Kalus, S.M., Kornman, L.H. & Quinlivan, J.A., 2008. Managing back pain in pregnancy using a support garment: a randomised trial. BJOG : an international journal of obstetrics and gynaecology, 115(1), p.68-75.
Ho, S.S.M. et al., 2009. Effectiveness of maternity support belts in reducing low back pain during pregnancy: a review. Journal of Clinical Nursing, 18 (11), 1523-1532.