Definition
The Piriformis syndrome and occurs very often during pregnancy. The growing child in the uterus presses on the piriformis muscle in the deep hip muscles, which becomes inflamed by the pressure load. Below the muscle, the sciatic nerve runs in the foramen infrapiriforme, which is compressed by the loaded muscle. As a result, pain occurs in the gluteal region, which can radiate from the thigh down to the knee.
Causes of Piriformis Syndrome in pregnancy
The cause for the occurrence of piriformis syndrome during pregnancy is the increase in size of the uterus due to the growing fetus. During pregnancy, the uterus presses more and more on the deep hip muscles, thereby compressing the sciatic nerve (sciatica). The sciatica emerges from the spinal cord between the lumbar vertebrae and reaches the buttocks and the thigh muscles under the piriformis muscle, which it supplies with motor and sensory energy.
Compression typically causes pain in the buttocks, which extends over the leg to the knee. Sometimes the pain is also difficult to localize and radiates from the buttocks to the back and groin. Due to the changed center of gravity caused by the growing abdomen, pregnant women shift their weight backwards, which increases the pressure on the sciatic nerve and causes the pain. Another reason why the piriformis syndrome preferentially occurs during pregnancy is that women’s weight increases as the pregnancy progresses. As a result, the sciatic nerve is often compressed and causes pain.
The accompanying symptoms
In addition to the pain in the buttocks and leg, other symptoms similar to those of sciatica irritation occur during pregnancy in the case of piriformis syndrome. However, unlike sciatica syndrome, back pain does not occur because the nerve is not compressed when it exits the spinal cord, but only when it passes through the hip muscles. The pain increases after long standing or walking.
Even long periods of sitting, such as when driving a car, increase the pain. Other symptoms are sensory discomfort, such as tingling, and sensitivity disorders along the buttocks and lateral thigh. Irritation of the nerve can also lead to numbness in the affected leg. When sitting, the sciatic nerve becomes increasingly pinched and the symptoms worsen. The pain in the buttocks also worsens when climbing stairs or after strenuous activities such as long walks or standing.
