Carpal Tunnel Syndrome During Pregnancy

During pregnancy, a woman’s body changes in many different ways. Some of these changes are due to hormonal fluctuations. Others are caused by the additional mechanical stress on the musculoskeletal system of carrying another human being in one’s uterus. It is important to be aware of what these changes are so that you can better understand what’s happening in your body and learn ways to support the changes to be as comfortable as possible.

Carpal tunnel syndrome (CTS) is common among pregnant women. Approximately 34% of women report symptoms of CTS during pregnancy. Compare this to the 4% of non-pregnant women who experience CTS. Most of the symptoms emerge in the third trimester and occur in both wrists. The most common symptom is tingling of the fingers at night. Though this sounds like not a big deal, it can be incredibly uncomfortable, distracting and get in the way of daily activities. Other symptoms include weakness of grip, stiffness of fingers and numbness in the thumb side of the hand. Even though over a third of pregnant women report symptoms associated with CTS, these complaints are often not addressed either because the woman’s care provider does not ask about it, or because the symptoms are considered mild and are not brought up by the expecting mother. However, mild to moderate discomfort in the hand and wrist could have implications beyond the musculoskeletal component and should be addressed before those issues emerge.

Carpal tunnel syndrome is caused by compression of the median nerve in the carpal tunnel. The carpal tunnel is a small passageway in the wrist that is bordered by bone and an inflexible ligament called the carpal ligament. There are several structures that run through the carpal tunnel, including muscle tendons that attach onto the fingers, and the median nerve, which provides sensory and motor innervation to the thumb side of the hand. The symptoms associated with carpal tunnel result from compression and impairment of the median nerve. This compression can be caused by an increase in fluid, resulting in edema (swelling) in the wrist joint. It can also result from inflammation of the synovial sheaths surrounding the muscle tendons. This inflammation is usually caused by repetitive movement of the fingers when the wrist is in an extended position, such as when typing on a keyboard without wrist support. During pregnancy, the most likely cause is swelling due to fluid retention in the body, which can be exacerbated by repetitive movement. An increase of fluid retention is one of the symptoms that correlate strongly with symptoms of CTS in pregnant women. There is a normal amount of swelling that is expected during pregnancy, and even within this normal range, CTS can occur.

On the whole, the severity of symptoms in pregnant women tend to be less than those in non-pregnant women, even though more pregnant women have symptoms. However, since most of the symptoms in pregnant women occur at night, they can interfere with women getting a restful night sleep. So even if the CTS symptoms themselves are mild, the consequences of the lack of sleep can be more severe. Poor sleep can put patients at risk for mild depression and anxiety. It makes a huge difference for women to transition to motherhood as well rested as possible, so even mild cases of CTS should be reported to one’s doctor so that symptoms can be addressed and relief found.

Luckily, there are some easy and effective methods of alleviating symptoms. Using a wrist splint at night proved helpful to 80% of participants in a recent study. Dietary factors that can reduce swelling include lowering the amount of sodium intake and increasing the amount of potassium intake. Bananas are a favorite source of potassium for many people. Inactivity is also a contributing factor. Yoga can also provide relief through movement.

Recommendations to reduce symptoms of CTS:

1. Wear a wrist splint at night.

2. Eat more potassium. Sweet potatoes, spinach, tomato sauce, black beans, white beans, butternut squash and watermelon are all great sources.

3. Eat less salt

4. Light exercise

Please make sure to check with your doctor and let her know about any symptoms you have related to carpal tunnel syndrome or to excessive swelling due to fluid retention. With some minor changes, women can find a lot of relief and increase enjoyment of their pregnancies!
carpal tunnel.001Image 1: Front of wrist showing the bones and ligaments of the carpal area. The carpal ligament lies on top of several muscle tendons, shown in gray, and the median nerve, in yellow.

carpal tunnel.002

Image 2: Cross-section of the wrist showing the area of the carpal tunnel bordered in blue. You can see the muscle tendons and the synovial sheaths covering them as well as the median nerve (in yellow).