Posterior Pelvic Pain (Sacroiliac Joint Pain) in Pregnant Women
Posterior pelvic pain (PPP) is pain felt at or near the sacroiliac joints of your pelvis as a result of sacroiliac joint dysfunction.These are joints located at the 2 dimples of the lower back. The pain often feels deep within your lower back and can occur on one or both sides of your back. In some cases, pain radiates down to the buttock and the back of the thigh.
While pain may begin at any time during pregnancy, PPP on average begins in the 18th week of pregnancy and becomes more intense as the pregnancy progresses. The pain usually spontaneously resolves within 3 months post delivery. But in some cases it can become chronic and disabling.
What are the Sacroiliac joints?
The sacroiliac joints (SIJ) are formed between the sacrum, a triangular-shaped bone in the lower portion of the spine, and the right and left ilium of the pelvis. The SIJ is a strong and stable weight-bearing joint that permits very little movement due to its natural structure. The main role of the SIJ is to allow forces to be transmitted effectively through the body, absorbing impact from the legs to the spine during activities such as walking, running and jumping.
The SIJ is kept stable through two mechanisms:
- Firstly, the rough, groove-like connecting surfaces of the sacrum and ilium interlock and help stabilise the joint, like two pieces of Lego together.
- Secondly, the SIJ is further strengthened by a complex mesh of ligaments and muscles such as the core stabilizers. These core muscles, such as the transversus abdominis and multifidus which surround the SIJ, act as active stabilizers by actively contracting to create a compressive force over the SIJ, gripping the joint firmly together. They act as a natural corset by providing that compression around the lower back and pelvic region -much like wrapping your fingers around the two Lego pieces, keeping them firm and tight.
Posterior pelvic pain arises from sacroiliac joint dysfunction, in other words, when the stability of SIJ is compromised.
Why does it happen?
During pregnancy, mechanisms stabilising the SIJ is affected. This instability allows for increased motion, stressing the SIJ.
- Hormones released during pregnancy relax the ligaments of the body to allow the pelvis to enlarge, in preparation for childbirth
- Due to the growing uterus, some of the core muscles around the pelvis get ‘stretched’ and weakened.
Moreover, the additional weight and altered walking pattern associated with pregnancy can cause significant mechanical strain on the sacroiliac joints, which may result in SIJ inflammation, giving a deep ache in the posterior pelvis.
What are the symptoms?
Of all the back pains experienced during pregnancy, posterior pelvic pain is the most common – you are four times more likely to experience PPP than lumbar pain.
You may have posterior pelvic pain / sacroiliac joint dysfunction if you have:
- Deep, boring pain in the back of the pelvis (around the sacroiliac joints)
- Pain may occasionally radiate to the groin and thighs.
- The pain is typically worse with standing, walking, climbing stairs, resting on one leg, getting in and out of a low chair, rolling over and twisting in bed, and lifting. The pain improved when lying down.
- If there is inflammation and arthritis in the SI joint, you may experience stiffness and a burning sensation in the pelvis.
Diagnosing Sacroiliac Joint Dysfunction in pregnancy
Your doctor and/or physiotherapist will conduct a thorough history and physical examination to determine the underlying disorders for your pain. That includes your description of symptoms, a series of tests designed to look at the stability, movement, and pain in the sacroiliac joints and surrounding structures. Imaging, such as computed tomography (CT) scan and X-ray may also help in the diagnosis. Another reliable diagnostic method involves injecting an anesthetic agent into the SI joint, guided by an X-ray machine, numbing the irritated area, thereby identifying the pain source. However, due to the concerns of fetal exposure to radiation, diagnostic procedures involving radiation is generally avoided.
Treatment and Management
The first-line treatment of pregnancy-related sacroiliac joint dysfunction is physiotherapy and exercises that focuses on core stability of the trunk and pelvic girdle. Sometimes, a sacro-iliac belt is prescribed to complement the core stability exercises and to give quick pain relief. Exercises will form a large part of the treatment and in some cases, mobilisation (a gentler form of manipulation) of your hip, back or pelvis may be used to correct any underlying movement dysfunction. Other manual techniques include muscle energy technique (MET) and myofascial release. It is vital to engage a physiotherapist who is skilled in treating pregnancy-related pain as she is aware of the studies that support the use of specific stabilizing exercises and other treatment techniques, thereby preventing the dysfunction from escalating into a chronic condition.
Other alternative treatments include anesthetic and steroidal injections into the SIJ that can help in pain relief, which lasts from one day or much more long-term. Oral anti-inflammatory medications are often effective in pain relief as well. However, these two treatments may be contra-indicated during pregnancy.
Posterior Pelvic Pain Home Advice
Here are some tips for expectant women with posterior pelvic pain..
- Avoid lying on your back for long periods of time, particularly after the 19th week of your pregnancy.
- Try lying on your side (preferably your left) with a pillow placed between your knees and another under your tummy.
- If your waist sags down into the bed, try placing a small rolled up towel under your waist.
Turning over in bed
- To turn to your right while lying on your back, arch your lower back, tighten your pelvic floor muscles and lower abdominal muscles and bend both knees one by one.
- Turn your head to the right and take your left arm over to the right of your body. Hold onto the side of your bed if you can.
- To turn, pull with your left hand and take both knees over to the right so that you roll to the right. As soon as possible, bend your knees up as high as they will go – this helps to lock out your pelvis and lessen pain.
- Reverse this to turn to the left.
Getting out of bed
- Roll onto your side with your knees bent up, move your feet over the edge of the bed and push yourself up sideways with your arms.
- Reverse the process when you lie down.
Standing from a sitting position.
- Sit on the edge of the chair.
- Keeping your knees apart slightly and lean forwards till your head is directly over your knees, keeping your back straight.
- Stand up by pushing up with your arms, with your back straight and tummy tucked in. This helps to hold your pelvic joints in their most stable position and may reduce your pain significantly.
- Fitzgerald CM and Le J. Back pain in pregnancy requires practitioner creativity. Biomechanics. 2007 November
- Ostgaard HC, Andersson GB, Karlsson K. Prevalence of back pain in pregnancy. Spine. 1991; 16:549-552.
- Ostgaard HC, Zetherstrom G, Roos-Hansson E, Svanberg B. Reduction of back and posterior pelvic pain in pregnancy. Spine. 1994; 19:894-900.
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