Objective: The present study aimed to characterise grandmultiparous women receiving intra-partum epidural analgesia and investigate associations between this method of pain relief and labour outcomes in grandmultiparas.
Methods: A population-based study was conducted comparing obstetric and perinatal characteristics of grandmultiparous women with and without epidural analgesia. Deliveries occurred during the years 1988-2006. Multiple logistic regression models were constructed to find independent risk factors associated with epidural analgesia, cesarean section and 1st stage labour dystocia.
Results: Out of 41,488 deliveries to grandmultiparous women included in the study, intra-partum epidural analgesia was utilised in 877 (2.1%). Multivariate analysis revealed that grandmultiparas who received epidural pain relief were significantly older and more likely to suffer from pre-mature rupture of the membranes, polyhydramnion, oligohydramnion, labour induction and a macrosomic fetus. After controlling for potential confounding, use of epidural analgesia remained an independent risk factor for 1st stage labour dystocia (odds ratio (OR) = 1.5; 95% confidence interval (CI) = 1.08-2.2) and cesarean delivery (OR = 2.9; 95% CI = 2.4-3.5) in grandmultiparas.
Conclusion: Grandmultiparous women who received intra-partum epidural analgesia have entirely different obstetric characteristics as compared with those who did not receive this method of pain relief. Although epidural use was demonstrated to be an independent risk factor for 1st stage labour dystocia and cesarean section in this population, residual confounding cannot be excluded.