Pregnancy Related Low Back Pain View PDF

Pregnancy related LBP is a common complaint among pregnant women. It can have a negative impact on the life of pregnant women. LBP during pregnancy has been recognized for many centuries and was described by hippocrates, vesalius, pinean, hunter, velpeau and many others. In 1962 Walde was the first who recognized the differences between PGP and LP [1]. About 50% of pregnant women will complain from LBP during their pregnancies or the postpartum period [2]. Several factors account for pregnancy related LBP such as mechanical, hormonal and other [3].

Pregnancy related LBP present either as a PGP between the posterior iliac crest and the gluteal fold or as a LP over and around the lumbar spine. Although, a small group of women suffer from combined pain. PGP is common during pregnancy and postpartum period and approximately four times as prevalent as LP. It is described as deep, stabbing, unilateral or bilateral, recurrent or continuous pain, presenting between the posterior iliac crest and the gluteal fold, possibly radiating to the posterolateral thigh, to the knee and calf, but not to the foot [4]. PGP is more intense during pregnancy than during postpartum period. The posterior pain provocation test (PPPT) is positive [5].

LP during pregnancy describe as pain over and around the lumbar spine, above the sacrum, may or may not radiate to the foot, tenderness over paravertebral muscles is a common finding. More intense at postpartum period than during the pregnancy and exacerbates by certain activities and postures (e.g. prolong sitting) but it seems to be less disabling than PGP [5]. The PPPT is negative, LP and PGP should be diagnosed and differentiated early, since the treatment is different for each condition. LBP is the most common cause of sick leave after delivery [6]. The treatment aims to reduce the discomfort and the impact on the pregnant woman’s quality of life.

Early identification and treatment will lead to the best possible outcome. Conservative management is the gold standard including physiotherapy, stabilization belts, nerve stimulation, pharmacological treatment, acupuncture, massage, relaxation, and yoga [7]. Many studies show that the prevalence of pregnancy related LBP range from 25% - 90%, with most studies estimating that 50% of pregnant women will suffer from LBP. One third of them will suffer from severe pain, which will reduce their quality of life. The majority of women are affected in their first pregnancy [8].

20% of pregnant women will experience PGP. Pregnancy related LBP usually begins between the 20th and the 28th week of gestation, however it may have an earlier onset and the duration varies. A study about PGP in Netherlands shows that 38% of women still have symptoms at 3 months postpartum and 13.8% at 12 months [9]. Existing literature supports LBP as the leading reason for sick leave, as far as pregnant working women are concerned is poorly understood [6].

Various explanations on the pathophysiology of pregnancy related LBP have been suggested. One of the most accepted hypotheses is the association with the mechanical factors, due to weight gaining during pregnancy, the increase of the abdominal sagittal diameter and the consequent shifting of the body gravity center anteriorly and increasing the stress on the lower back [6]. Studies suggest that an anterior shift is associated with pubic symphysis problems [10]. Postural changes to balance this anterior shift, causing lordosis and increasing stress on the lower back [11]. The connection between LBP and pelvic floor dysfunction has been suggested. A negative active straight leg raise test in combination with a positive PPPT may be interpreted as an increased activity of the pelvic floor muscles, in order to compensate for pelvic stability [12].

Decrease the height of the intervertebral discs during pregnancy results in major compression of pregnant women spine with LBP which also takes longer to recover in comparism to women without LBP [10]. Weakness of abdominal muscles of the pregnant woman due to stretch to accommodate the enlarging uterus, put an extra load on the spine, which is charged to support the increased weight of the torso [6, 10]. Weakness of the gluteus medius is strongly related to the presence of LBP during pregnancy [13].

Since significant percentage of pregnant women firstly complain LBP during the 1st trimester of pregnancy in absence of any disease or trauma to initiate the condition and mechanical changes not so mark to account for pain induction, this suggest that the body of the pregnant is exposed to certain factors causing dynamic instability of the pelvis causing LBP such as hormonal changes. Relaxin increases tenfold during pregnancy causing ligamentous laxity and discomfort, not only in the Sacro-iliac joint, but also cause generalized discomfort. The association between circulating levels of the hormone relaxin and LBP in pregnancy is under debate [2, 6].

Another theory suggests that expanding uterus press on the vena cava causing venous congestion in the pelvis and the lumbar spine [10]. Sciatica is a rather rare clinical entity of LBP during pregnancy, appearing in only 1% of women. Sciatica may be the result of herniation or bulging of an intervertebral disc, causing nerve compression [10]. In a small group of women, the persistent pain during postpartum period may be secondary to osteitis condensans ilii [14].

There has been a lot of debate about the risk factors of pregnancy related to LBP. History of pelvic trauma, chronic LBP and LBP during a previous pregnancy are the most common and widely accepted risk factors [10]. 85% of women with back pain in a previous pregnancy will develop back pain in a subsequent pregnancy [1, 15]. The number of previous pregnancies also seems to increase the risk [16]. It is not possible to estimate the risk, or to predict who will suffer from LBP during pregnancy, however, women with a history of LBP before pregnancy, are most likely to suffer from more severe pain and of a longer duration after childbirth. LP is more strongly connected with back pain history before pregnancy, compared to PGP. LBP during menstruation is an additional risk factor for pregnancy related LBP. A study using the Roland questionnaire suggests that the male sex of the fetus may be a predictive factor for back pain during pregnancy [17]. MacLennan and MacLennan [18] suggests that PGP is associated with dysplasia of the hip and a genetic susceptibility of the hip both of the mother and of the child. There is relative agreement that excessive body weight may be a risk factor for LBP during pregnancy [19] however, there are studies claiming that being overweight is not a risk for pregnancy related LBP [2]. Contraceptive pills and time interval since the last pregnancy are not considered as risk factors for LBP during pregnancy [2].

The association between the woman’s age or between high workload and LBP during pregnancy remains unclear [2, 6, 8]. Finally, it seems that epidural or spinal anesthesia during labour is not associated with a higher risk of persistent postpartum LBP [20]. Although it is difficult to prevent pregnancy related LBP, it possible for mothers, especially those on high risk, to follow some method as to reduce the possibility of having pregnancy related LBP [21].

Pregnant women should be educated on how they can maintain a proper posture, while doing everyday activities, so that their back is not overloaded and misaligned. That can be easily performed if practiced and can be enhanced by aerobic or physiotherapy exercises, preferably before pregnancy. 12 week training program during pregnancy is effective in the prevention of LBP, at 36 weeks of pregnancy [22]. Physical activity before pregnancy is correlated with a decreased risk of having LP, but not apply to PGP [4]. Women should be advised to use proper seats, cushions and beds, as well as techniques for getting in and out of bed. The most important factor determine the prognosis of LBP during pregnancy is the actual progression of pregnancy [23].

In general, the prognosis is good for most women with pregnancy related LBP. Combined pain during pregnancy is a predictor for persistent PGP or combined pain postpartum [24]. One of the most important risk factors for postpartum LBP is previous pregnancy related LBP. Intensity of the pain is a prognostic factor. Women with high postpartum weight gain at high risk for postpartum LBP [9].

Only 50% of women suffering from pregnancy related LBP will seek advice from a health care professional and 70% of them will receive some kind of treatment [25]. Early identification and treatment, taking under consideration the individuality of every woman and pregnancy, provide the opportunity for the best possible outcome. Conservative management of LBP is the treatment of choice. A correct diagnosis and a differentiation between PGP and LP is very important, since the treatment is different [2, 6, 10]. Some of the treatment options are physiotherapy, stabilization belts, nerve stimulation, pharmacological treatment, acupuncture, massage, relaxation, and yoga. Weight loss strategies during postpartum and prevention of weight gain may help to prevent the risk and the severity of LBP [26].

There are studies demonstrating that sterile intradermal water injections induce a significant, dramatic analgesic effect for women that experience LBP during labour, lasting from 10 min and up to 2 h post administration. Their effect has been described as powerful, rapid and effective; with the potential to decrease or delay the use of epidural anaesthesia [27]. Acupuncture seems to alleviate LP and PGP during pregnancy, while it increases the capacity for some physical activities and helps diminish the need for drugs, which is a great advantage during this period. However the treatment effect was not sustained in some of the pregnant women. Thus, long-term efficacy is still inconclusive but clearly promising [28]. The basic management of PGP is different from that of LP. Pharmacological agents are not mentioned in the literature as a possible alternative treatment during pregnancy. In cases of persistent pain combinations of methods should be considered [29].