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TheAnswerPage/Obstetrics & Gynecology
Monday
February 08, 2010
This week:
Musculoskeletal disorders in pregnancy
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What is the most likely cause of her pain?
Low back pain is a common complaint during pregnancy, and is
reported in up to 80% of pregnant women (1). The high prevalence of
low back pain in pregnancy has been attributed to progressive lumbar
lordosis and increased mobility of the pubic symphysis, sacroiliac,
and sacrococcygeal joints. These changes are thought to be due in
large part to the effects of the relaxin hormone on the
musculoskeletal system (2). In 20% of cases, the pain is sufficiently
severe to cause prolonged disability. Lumbar disk herniation should
also be considered in pregnant women presenting with considerable
back or leg pain.
What are the risk factors for low back pain in
pregnancy?
Major risk factors for low back pain in a given pregnancy include
back pain in a prior pregnancy, back pain prior to pregnancy, and
increased body mass index.
How should this patient be managed?
Parturients with moderate to severe low back pain should be
managed in collaboration with specialists in pain medicine. Treatment
options include physical therapy, support braces, transcutaneous
electrical nerve stimulation (TENS), epidural depot steroid
injection, or trigger point injections (3). Non-steroidal
anti-inflammatory drugs should be prescribed with caution in
pregnancy, especially in the third trimester, because they are
associated with premature closure of the ductus arteriosus leading to
pulmonary hypertension and with decreased fetal urine output and
resultant oligohydramnios. Acetaminophen with codeine can be given
for more severe pain. Chronic narcotic therapy is associated with
dependence, and should be avoided. In cases of severe low back pain
and/or neurologic deficit, magnetic resonance imaging should be
considered to rule out lumbar disk herniation and space-occupying
lesions, which can cause nerve root compression.
The mode of delivery does not appear to effect the natural history
of low back pain in pregnancy. Intrapartum regional analgesia is not
contraindicated in parturients with a history of low back pain, and
should be offered to all parturients in labor in the absence of known
pathology or neurologic deficit. That said, informed consent for
regional anesthesia should include the fact that available data on
the association between regional anesthesia and postpartum low back
pain are conflicting.
Question Author: Mehmet Genc, M.D., Ph.D., Clinical Instructor,
Harvard Medical School
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References:
- Kristiansson P, Svardsudd K, Schoultz BV. Back pain during
pregnancy: a prospective study. Spine 1996; 21:702-9.
- MacLennan AH, Nicolson R, Green RC. Serum relaxin in
pregnancy. Lancet 1986; 2:241-3.
- Bonica JJ. Bonica's Management of Pain, 3rd Edition.
Philadelphia: Lippincott Williams & Wilkins, 2001.
Site Editor: Errol Norwitz, M.D., Ph.D. Department of Obstetrics and Gynecology, Harvard Medical School
Founders
and Editors-in-Chief: Stephen B. Corn, M.D. and B. Scott Segal,
M.D.
Department of Anesthesiology, Perioperative and Pain Medicine, Harvard Medical School
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