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In this space, we talk a lot about illnesses which can affect pregnant women and their newborns. So it might surprise you to read about something that might more often be a problem for someone with grandchildren or even great-grandchildren. However, as we know from the current crisis, there are many things out there that are associated with disease in oldsters but can cause problems in young adults—including pregnant women. And one of those conditions is known as lumbar spinal stenosis (LSS).
The Spine, and What Can Happen To It
The spine, or backbone, is made up of individual, fairly small bones called vertebrae. The vertebrae are, in a sense, donut-shaped; that is, they have a largish hole in the center through which the spinal cord runs. The spinal cord contains nerves. Through smaller holes in the vertebrae, these nerves all exit the spinal cord at various points down its length to provide for sensation (touch, pain, warm, cold), movement and other functions.
Sometimes, the “hole of the donut”—otherwise known as the spinal canal—can become smaller. (We’ll go into why that might happen in a little bit.) Also, the smaller holes where the nerves exit to the body can become even smaller. If these things happen, there can be a couple of problems. First off, you might feel pain in your back from the pressure on the nerves. Most commonly, the pain is in the lower back, buttocks, and legs and may be worse with regular walking. Second, because of the ways the nerves run to parts of your body after they exit the spinal column, you may feel pain down the length of a nerve. Finally, the nerves affected by that part of the spine may not work as well, leading to numbness and weakness.
Getting “Whys” to Lumbar Spinal Stenosis
Who’s most at risk for LSS? It turns out to be the elderly, people over 60. They’ve had a lifetime of using their spines which can lead to degenerative changes in the vertebrae, making those holes narrower and pressing on the nerves.
However, there are other causes of LSS, many of which may affect younger people. Some are born with it, and although it may not always cause symptoms right away, problems may arise in young adulthood. In addition, disease such as rheumatoid arthritis and ankylosing spondylitis may cause the vertebrae to change for the worse early on.
Injury to the spine is yet another cause of lumbar spinal stenosis. Most commonly this causes the vertebrae to misalign and put pressure on the spinal cord. Even a mild traumatic injury such as one might get in sports can do this. One of the more common causes in this category is something called spondylolisthesis, where movement of the spine from, say, certain sports activities causes the vertebrae to get out of line. Those of us who care for teenagers are used to seeing it once in a while in gymnasts.
Finally, LSS-type symptoms can happen due to problems with the intervertebral discs, the jellylike structures in between the vertebrae that hold them together. It isn’t unusual for 30-something adults to develop problems with the discs. One problem is that of herniation, when part of the disc enters the spinal column due to strain on the back. Another problem is degenerative disc disease, when the disc material dehydrates and loses its shape, causing changes in the bones of the vertebrae.
What to Do
Although there doesn’t appear to be any evidence that pregnancy causes increased symptoms from LSS, pregnancy can certainly be associated with back pain. Certainly, any back pain that bothers you or any that lasts more than a couple of days should be reported to your obstetrician. And by all means, let her know if you have any conditions that commonly cause back pain, including LSS.
If you aren’t aware of any specific history or risk for LSS, there are a few clues. Any pain that goes down an arm or leg as well as any numbness, tingling or weakness may mean that you’re not dealing with common pregnancy back pain, which tends to be limited to the back.
If LSS is suspected, your provider might choose to do an MRI, which is generally thought to be a safer test for a pregnant woman than a CT scan. And the initial treatment is really just an amped-up version of what would be recommended for any back pain in a pregnant woman: rest, exercises, and pregnancy-friendly pain medication. Physical therapy is always an option. Surgical treatment is available—ideally after delivery.
A lot of pregnant women will have back pain. Not many will have LSS. But the most important thing to take away is to know your history and continue to discuss your symptoms with your obstetrician.