pregnacy low back pain


A Time of Change

Pregnancy can be an exciting time for a mother and her loved ones, but it is also a time of great physical and emotional change.  Sickness and discomfort are commonly experienced and often expected during  pregnancy.  One such discomfort is low back pain, which is reported to affect 1 in 2 pregnant women.  Many patients are told that while treatment is available, back pain is best relieved through delivery. This may be true in some cases, but research reports that nearly 10% if all pregnant women experience low back pain severe enough to require  bedrest, absence from work, or limit other daily activities.  Other researchers have explained that pain originating from a specific joint (called  the sacroiliac joint) can continue for several months after delivery.  In cases such as these, low back pain cannot be ignored.  Treatment is readily available and it is also possible to significantly reduce or eliminate such pain.


Defining Low Back Pain During Pregnancy


Low back pain during pregnancy could be classified into three types.  Lumbar pain, sacroiliac  pain, and nocturnal pain.


Lumbar pain:

Lumbar pain can originate from one or multiple sites in the low back and can occur with or without pain radiating down the legs.  The pain can be associated with the muscle, joints, and/or supporting ligaments.  Lumbar pain can also be aggravated by prolonged sitting or standing and is usually located throughout the low back.


Sacroiliac pain:

Sacroiliac pain may also include some radiating sensations, however it is usually located specifically deep in the buttocks. These symptoms are commonly sharper, more painful, more debilitating and can for several months after delivery.  Unfortunately, studies have shown that sacroiliac pain is 4 times more likely than lumbar pain.  Sacroiliac pain is aggravated by any prolonged posture, especially during weight-bearing.  Pain while turning in bed at night is also a complaint that may be associated with sacroiliac pain. Furthermore, it is thought that 20-30% of pregnant women experience both lumbar and sacroiliac pain.

As the pregnancy progresses, the hormone relaxin is released more prominently within the body allowing the pelvis to expand and accommodate to the enlarging uterus as well as prepare for delivery. Some studies have reported the pelvis to widen up to 12millimeters during pregnancy.  Moreover, the production of the hormone relaxin increases tenfold, peaking at the 14th week, and can also affect other joints in the body.  This may be why some pregnant women complain of “creaking” joints and unproved ankle injuries.

pregnancy sidelying

Nocturnal pain:

Nocturnal pain will exclusively occur during sleep (presumably at night).  It may be described as a low-back cramp similar  to a low-back ache of menstruation.  It may also be severe enough to disturb sleep.  Unlike sacroiliac pain or lumbar pain,  pain while turning in bed at night will not be experienced.

As the uterus enlarges, it places pressure on organs and tissues within the abdomen.  When a pregnant woman lies on her back, the uterus obstructs a major vein returning blood to the heart.  This forces more blood than usual to be returned to the heart via other smaller veins and is thought to be the cause of night backaches.