Associations between the number of children, age at childbirths and prevalence of chronic low back pain: the Nord-Tr\xf8ndelag Health Study

Ingrid Heuch,John-Anker Zwart,Ivar Heuch,Knut Hagen,Kjersti Storheim

doi:10.1186/s12889-020-09480-0

Abstract

BackgroundAssociations between childbirths and subsequent risk of low back pain (LBP) have not been clarified. Changes in sex hormone levels or lumbar posture during pregnancy may have an impact on LBP later in life. The purpose of this study was to explore associations between the number of childbirths, age at childbirths and prevalence of chronic LBP in a general population of women.MethodsData were obtained from the Norwegian community-based Nord-Trøndelag Health Study, HUNT2 (1995–1997). Women aged 20–69 years indicated whether they suffered from chronic LBP, defined as LBP persisting at least 3 months continuously during last year. Information about LBP was collected from 3936 women who had experienced no childbirths, 3143 women who had delivered one child only and 20,584 women who had delivered 2 or more children. Of these, 7339 women reported chronic LBP. The 595 women who were pregnant when information was collected were considered separately, regardless of previous births, with 80 women reporting chronic LBP. Associations with prevalence of chronic LBP were examined by generalised linear modelling with adjustment for potential confounders in a cross-sectional design.ResultsWomen who had delivered one child only showed a higher prevalence of chronic LBP than women with no childbirths (prevalence ratio (PR) 1.11; 95% CI: 1.01–1.22). Among women with one or more childbirths, no overall change in prevalence could be demonstrated with an increasing number of children in analyses adjusted for age at first delivery. In women with at least two childbirths, an age less than 20 years at first childbirth was associated with an increased prevalence of chronic LBP (PR 1.36; 95% CI: 1.25–1.49; compared with age 25–29 years). No association was observed between age at last delivery and chronic LBP. The lowest prevalence of chronic LBP was found among women who were currently pregnant (PR 0.80; 95% CI: 0.63–1.00; compared with women with no childbirths).ConclusionsHaving experienced at least one childbirth seems to be associated with a higher prevalence of chronic LBP later in life. A young age at first childbirth is also associated with a long-lasting increased prevalence.

Highlights

Associations between childbirths and subsequent risk of low back pain (LBP) have not been clarified
Similar but weaker increases in the number of children were observed among women with body mass index (BMI) ≥ 25, among those with a large Hospital Anxiety and Depression Scale (HADS) score, women reporting little physical activity and among former smokers
A tendency to an increasing prevalence with more childbirths after the first was seen in initial analyses, at least among women with 1–4 births, but mainly disappeared after adjustment for age at first childbirth (Table 2)

Summary

Introduction

Associations between childbirths and subsequent risk of low back pain (LBP) have not been clarified. It has been hypothesised that such pregnancy-related LBP may be related to changes in lumbar posture, perhaps combined with stretching of abdominal muscles or particular hormonal influences in pregnancy [3]. It is not clear, whether going through a pregnancy increases a woman’s long-term risk of LBP. Whether going through a pregnancy increases a woman’s long-term risk of LBP Such long-lasting effects may be related to more general hormonal or mechanical changes associated with pregnancies [4]. A large population-based cross-sectional study [10] found an increased prevalence of LBP among women who had ever been pregnant, no trend was seen according to the number of pregnancies

Objectives

Methods

Results

Discussion

Conclusion