Paracetamol prior to catheter balloon insertion for labor induction—A randomized controlled trial

Background: Assessing maternal pain and satisfaction following administration of paracetamol vs. placebo prior to catheter balloon placement. Methods: Primiparous women at term admitted for medically-indicated labor induction were randomized to receive intravenous paracetamol 1 gram in 100cc normal saline (N=71) or placebo of 100cc normal saline (N=70) prior to catheter balloon insertion. The women were blinded to the intervention allocation. Primary outcomes were visual analog scale (VAS) scores and maternal satisfaction, assessed via questionnaire. Results: Pre-induction maternal pain did not differ between the paracetamol and placebo groups. Median VAS scores at 2, 30, and 60 minutes after catheter insertion were comparable between the groups: 6.46±2.77 vs. 6.66±2.78, P=.68; 5.53±3.20 vs. 5.93±3.01, P=.46; and 5.83±3.25 vs. 6.49±2.88, P=.26, respectively. For the paracetamol vs. placebo group, the mean sum of VAS scores was lower (4.39 vs. 5.37, P=.045) and the proportion with a mean VAS score <5 was higher (65.2% vs. 44.1%, P=.016). This difference persisted in a multivariate logistic regression analysis adjusted for maternal age (OR=2.2, 95% CI 1.1–4.5, P=.036). After balloon insertion, relatively fewer women in the paracetamol vs. placebo group showed immobility (33.8% vs 50.0%, P=.037) and needed analgesics (31.3% vs. 66.1%, P<.001). Maternal satisfaction score was similar between the groups (P=.877). Cervical ripening, duration from catheter insertion to delivery, and labor and neonatal outcomes did not differ significantly between the groups. Conclusions: The administration of paracetamol compared with placebo prior to catheter balloon insertion was associated with lower VAS score and less analgesic use and maternal immobility.