title: Factors associated with back pain symptoms in pregnancy and the persistence of pain 2 years after pregnancy.
abstract: BACKGROUND
  Factors associated with back pain symptoms in pregnancy and the persistence of pain 2 years after pregnancy.
  
  
  OBJECTIVE
  To determine the prevalence of back pain during pregnancy and to delineate the factors associated with the development and persistence of such symptoms 2 years after delivery.
  
  
  METHODS
  Prospective observational cohort. Consecutive patients in a low-risk obstetric population with singleton pregnancies were surveyed for back pain symptoms during pregnancy in the early postpartum period by a structured questionnaire. Data from this survey were then correlated with the details of labor and pregnancy outcome, as well as epidemiological, occupation and work data. A follow-up questionnaire survey was administered 24 months after delivery to the group who reported back pain symptoms in the first survey. The absence/presence of persistent symptoms at 24 months was correlated with the characteristics of their pregnancy, as well as their daily life activities at the time of the survey.
  
  
  RESULTS
  A total 326 patients with complete data were recruited. Two hundred and fifty (76.6%) reported one or more significant episodes of back pain during their pregnancy. Significantly more patients with presence of pain in pregnancy had history of previous back pain episodes when not pregnant (48% vs. 19.7%, p < 0.001), as well as during previous pregnancies (66% vs. 40%, p < 0.025), or in the postpartum period (40% vs. 6.6%, p < 0.001). There was no significant difference between those with or without pain in their pregnancy outcome. Complete data on 189 of the 250 study patients (75.6%) were available for analysis at 24 months after delivery. The incidence of persistent back pain symptoms was 21.1% (n = 40). Those with persistent pain were older, had significantly earlier onset of pain symptoms in the index pregnancy compared with those without pain at 24 months, and they also had their worse symptoms at an earlier gestation during the index pregnancy. Moreover, those with persistent pain had a higher weight gain at 24 months compared with their preindex pregnancy weight (6.8 kg, SD3.0) compared with those without further pain (4.0 kg, SD2.8) (p < 0.01), as well as less weight loss compared with their early postpartum weight (8.1 kg, SD4.8 vs. 1.1.5 kg, SD5.6) (p < 0.01).
  
  
  CONCLUSIONS
  The main factors associated with development of back pain were previous episodes of back pain while non-pregnant or pregnant. The occurrence of back pain during pregnancy did not affect the pregnancy outcome. The main risk factors associated with persistent back pain at 24 months appeared to be the onset of severe pain at an early gestation in the index pregnancy, as well as the inability to reduce weight to their pre-pregnant level.
authors: Department of Obstetrics and Gynecology, United Christian Hospital, Hong Kong. wwkto@hutchcity.com
authors: W W K
authors: WW
authors: To
authors: M W N
authors: MW
authors: Wong
mesh_terms: D000328:Adult; D017677:Age Distribution; D016009:Chi-Square Distribution; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D017116:Low Back Pain / Q000175:diagnosis* / Q000453:epidemiology*; D010147:Pain Measurement; D049590:Postpartum Period; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis* / Q000453:epidemiology*; D011336:Probability; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D013997:Time Factors