Back pain is a common symptom that about 80% of women experience during pregnancy. There are many causes of why women get lower back pain when pregnant, and include the enlarging uterus that compresses retro-abdominal structures, compression of blood vessels, increased burden of weight on the vertebrae and back muscles, and hormonal changes. Women who experience back pain during pregnancy should therefore avoid aggravating activities. This type of back pain usually resolves within 6 months of delivery.
The experience of low back pain when pregnant can be attributed to different causes. One such cause is peripartum pelvic pain, which may begin at the onset of pregnancy or 3 weeks prior to delivery. The most common sites of peripartum pelvic pain are the pubic and groin areas, but it may also occur posteriorly in the sacroiliac joints and coccyx.
Another cause of back pain when pregnant is the expansion of the uterus due to the growth of the fetus. As the uterus expands, a pregnant woman’s center of gravity shifts and weakens the abdominal muscles. This leads to a change in posture called lumbar lordosis, which means the lumbar area becomes more curved. The increase in curvature puts a strain on the back muscles, leading to lumbar pain, which occurs at the waist level and may radiate to the legs. If the shift in posture leads to a compression of a nerve, back pain can also result.
Back pain when pregnant can also result from the normal weight gain that occurs in association with childbearing. The extra weight leads to more stress on the muscles and the joints of the back. This is the reason why back pain seems to be worse after prolonged periods without back support or at the end of the day.
Physiological hormonal changes that occur during pregnancy help loosen the ligaments and joints of the vertebrae and pelvis in preparation for childbirth. This loosening leads to a sense of instability and low back pain symptoms. The pain symptoms may be more prominent when walking, rolling over, bending, lifting, and sitting for prolonged periods.
Several measures can help prevent or ease the symptoms of back pain when pregnant. These include observing proper posture, sitting and standing with care, and lifting properly. When walking, it is best to wear low-heeled shoes with proper arch support.
Using a maternity support belt or maternity pants that feature a supportive waistband can help. Staying fit through regular exercise can help strengthen the back and abdominal muscles. Sleeping on the side reduces the stress on the back. The application of warm or cold packs, or back massage may also help relieve back pain associated with pregnancy.