Predicting persistent pregnancy-related low back pain

Study Design. A cohort study. Objective. To examine the course of subtypes of low back pain (LBP) experienced [no LBP, pelvic girdle pain (PGP), lumbar pain, and combined PGP and lumbar pain (combined pain)] during gestational weeks 12 to 18 and 3 months postpartum, and to explore potential predictors for persistent PGP or combined pain postpartum. Summary of Background Data. LBP is more prevalent in pregnant women (25%) than in the general population (6.3%). Persistent LBP postpartum (16%) is usually studied as a single entity. However, only one subgroup of LBP, pelvic girdle pain (PGP), is associated with pregnancy. Several studies have suggested an association between muscular dysfunction and pregnancy-related LBP, however, muscle dysfunction has not been evaluated as potential predictor of persistent LBP postpartum. Possible subgroup differences in the course and predictors of persistent LBP are unknown. Methods. Pregnant women (n = 308) were classified into LBP subgroups by mechanical assessment of the lumbar spine, pelvic pain provocation tests, standard history, and pain drawings. Trunk muscle endurance, hip muscle strength (dynamometer) and gait speed were evaluated. Multiple logistic regression was used to identify predictors from self-reports and clinical examination. Results. Women with combined pain recovered to a lower degree 33% (17 of 51) than those with PGP 66% (56 of 85) or lumbar pain 72% (21 of 29). Predictors for having persistent PGP or combined pain after delivery were low endurance of back flexors, older age, combined pain in early pregnancy and work dissatisfaction (explained variance 30%). Conclusion. Women with combined pain were identified to be a target group since they had the most unfavorable course and since the classification of combined pain was found to be a predictor for persistent pain postpartum. Identification of women at risk for persistent pain postpartum seems possible in early pregnancy and requires physical examination and self-reports. Pregnancy had low impact on the course of lumbar pain.