Factors associated with low back pain changes during the third trimester of pregnancy

(1) To investigate the course of pregnancy-related low back pain intensity and interference during the third trimester, and (2) to identify risk factors associated with changes in pain intensity and interference over time.

Pregnancy-related low back pain is common and reaches its peak both in the prevalence and severity in the third trimester.

A longitudinal design with consecutive sampling.

Three waves of data were collected from pregnant women in an antenatal care centre of a medical centre and a regional hospital in the northern Taiwan from February-June, 2010. Questionnaires were administered at gestational ages 28, 32 and 36 weeks. 214 women were enrolled and 179 participants completed all measures. Generalized estimating equations were used to identify the risk factors associated with changes in pain intensity and pain interference over time.

Pain interference increased over time during the third trimester. Pain catastrophizing and pain intensity at gestational age 24 weeks and time (from 28-36 weeks) were associated with increases in pregnancy-related low back pain intensity. These same factors plus depression were associated with an increase in pregnancy-related low back pain interference.

This study identified a number of prospective factors related to increases in pain intensity and pain interference during the third trimester. Given that both catastrophizing and depression are modifiable, the findings indicate that research examining the benefits of treatments that address these (e.g. cognitive-behavioural therapy) on pain and pain interference is warranted.