The high prevalence of low back and pelvic pain during pregnancy suggests that it is a major public health issue.

Back pain during pregnancy is mostly regarded as normal and is expected to spontaneously disappear after delivery. Half or more of pregnant women report back pain at some time during pregnancy, and it is also a common reason for sick leave.

Low back pain and pelvic pain is a common symptom during pregnancy, and the prevalence has been reported to vary from 24% to 90% in different studies. In one third of pregnant women, back pain is a severe problem compromising normal everyday life. Peripartum pelvic pain interferes with most activities of daily living and with sexual life. Back pain occurs twice as often in women with a history of back pain and women who have been pregnant previously. Younger women tend to have increased risk for back pain. Occurrence of pelvic pain is associated with twin pregnancy, first pregnancy, larger weight of the fetus, forceps or vacuum extraction, and a flexed position of the woman during childbirth. Women who experienced pelvic pain during a previous pregnancy report a relapse in 85% during a subsequent pregnancy. Women experiencing pelvic pain during pregnancy have been found to have normal height and weight and normal weight gain during pregnancy; however, body mass index has been reported to be significantly increased among first pregnant women with low back pain.

Although low back pain and pelvic pain during pregnancy is a most common complication of pregnancy, its cause is unknown and the mechanism is poorly understood. Some models propose increased spinal load and decreased stability in the pelvic girdle as major causes. Increases in abdominal diameter, fetal weight, and muscular dysfunction have been found to be associated with lower back pain and pelvic pain during pregnancy. A general increase in mobility of joints during pregnancy has also been described. Different attempts to investigate the cause of increased joint mobility during pregnancy have been made; the hormone relaxin was reported to be associated with pelvic pain during pregnancy. Reproductive hormones and procollagen in serum have been found to be associated with pelvic pain during late pregnancy. Oral contraception has also been investigated in relation to low back pain and pelvic pain during pregnancy with contradictory findings and it's use has been reported to influence the collagen metabolism.

Some authors consider low back pain and pelvic pain during pregnancy to be a normal condition of pregnancy. The symptoms may vary highly, and individuals are affected to different degrees. Nevertheless, referring to the actual scientific knowledge, this condition should be considered a complication of pregnancy for women with substantial impairment. For a small proportion of the affected women, the symptoms will not regress, and instead the condition may progress into chronic low back pain and pelvic pain after pregnancy.

According to a study in Spine. 2005 Apr 15;30(8):983-91, low back pain or pelvic pain during pregnancy was defined as recurrent or continuous pain for more than 1 week from the lumbar spine or pelvis during actual pregnancy.

There is a lack of a uniform classification of low back pain and pelvic pain during pregnancy. Low back pain is commonly defined as pain referred to the area between the twelfth rib and the gluteal folds. This anatomic area also includes the sacroiliac joints, which probably can be considered as a separate functional entity in the pathophysiology of pain in the pelvis. Other terms that are used are posterior pelvic pain, pelvic pain, pelvic girdle relaxation, and pelvic joint instability

History of previous low back pain and pelvic pain during pregnancy was associated with recurrence of low back pain and pelvic pain. Parity was a risk factor for low back pain and pelvic pain. Young women have been found to have more pain than older women; however, in other studies maternal age was not associated with level of pain or with prevalence of low back pain and pelvic pain during pregnancy. Prolonged pregnancy has been demonstrated to be significantly associated with low back pain and pelvic pain; however, gestational age per se was not related to low back pain and pelvic pain, and the prevalence of low back pain and pelvic pain at post-term was lower than the prevalence of low back pain and pelvic pain at term.

Women developing low back pain and pelvic pain weighed significantly more and had a significantly higher body mass index. The prevalence of hypermobility among women with pelvic pain has been estimated to be 12.8% to 17.3%. Diagnosed hypermobility or a family history of hypermobility was associated with an increased risk for low back pain and pelvic pain. This indicates the importance of hypermobility as a contributing factor to low back pain and pelvic pain during pregnancy.

A family history of low back pain and pelvic pain is associated with an increased risk for low back pain and pelvic pain. This association may correspond to inheritance or/and lifestyle factors.

The above study in Spine. indicated a majority of pregnant women report low back pain and pelvic pain. Parity, previous low back pain and pelvic pain, body mass index, a history of hypermobility and amenorrhea are factors influencing the risk of developing low back pain and pelvic pain. The high prevalence of low back pain and pelvic pain during pregnancy makes it a major public health issue, and efforts should be made to promote causal studies with the future aim of prevention and therapy of low back pain and pelvic pain. Different methods such as histologic examinations, immunology characterizations, and investigation of distribution of different hormone-receptors in connective tissue and muscle tissue may be possible attempts in discriminating deviating patterns in women with low back pain and pelvic pain during pregnancy.

According to a study in Spine. 2005 Apr 15;30(8):850-856, giving information about the condition along with a maternity support belt is beneficial, and exercises do not seem to have additional value when treating pregnant women. A non elastic pelvic support belt located just above the hips enhances stability. It is perhaps impossible to get any benefit from stabilizing exercises of the muscles around the pelvic girdle during pregnancy due to many natural changes in the body and limited time to exercise. Performing exercises has no additional value above giving a support belt and information. In fact, in a previous study in Spine. 1994 April 15; 19(8):894-900, it was shown that reduction of posterior pelvic pain by a pelvic support belt was experienced by 82% of the women with posterior pelvic pain.

A study in the International Journal of Nursing Studies. 2007 Jan;44(1):19-28 states "Promoting good posture and regular exercise can be recommended as a method to relieve back pain in pregnancy women." Advice to stay active within limits and use of a maternity body pillow or pregnancy body pillow to help with postural support while sleeping is reasonable.

In Applied Ergonomics. 2008 Dec 11; a study relating pregnancy and low back pain in working women indicates that staying in a "confined area" and "having restricted space" were positively correlated with severity of back pain at 34 weeks of pregnancy. The study suggests that allowing pregnant women to take more rest breaks and to have more job autonomy may reduce the severity of back pain during early pregnancy, and that allowing movement outside the working area and providing less restricted space may reduce back pain during late pregnancy.

Always treat women with respect and kindness. You never know when a woman may be pregnant, so helping women can promote a better and healthier next generation.