822 Implications of Intravenous Paracetamol Prior Labor Induction by Catheter Balloon Insertion: a Randomized Controlled Trial

For women with an unfavorable cervix, mechanical ripening by catheter balloon is common, but studies of pain relief during balloon insertion are lacking. This study aimed to assess maternal pain and satisfaction following paracetamol vs. placebo, prior to catheter balloon insertion. Primiparous women at term who were admitted for medically indicated labor induction were randomized to receive intravenous paracetamol 1 gram in 100 cc normal saline or placebo (100 cc normal saline) prior to catheter balloon insertion. The primary outcomes were visual analog scale (VAS) scores and maternal satisfaction, as assessed in a questionnaire. Overall, 141 women were included: 71 received paracetamol 1 g and 70 received placebo prior catheter balloon insertion. Background characteristics and pre-induction maternal pain did not differ between the groups. The median VAS scores at 2, 30 and 60 minutes after catheter insertion were comparable between the paracetamol and placebo groups, 6.46±2.77 vs. 6.66±2.78, p=0.68; 5.53±3.2 vs. 5.93±3.01, p=0.46; and 5.83±3.25 vs. 6.49±2.88, p=0.26, respectively. For the paracetamol vs. placebo group, the proportion with a mean VAS score < 5 was higher (65.2% vs. 44.1%, p=0.016) and the mean sum of the VAS scores was lower (4.39 vs. 5.37, p=0.045). After the balloon insertion, women in the paracetamol vs. placebo group showed greater maternal mobility (p=0.012), and a smaller proportion needed analgesics (31.3% vs. 66.1%, p‹0.001) (figure). The maternal satisfaction score was similar between the groups (P=0.877). In multivariate analysis, advanced maternal age (p=0.034) independently decreased the VAS score. Cervical ripening, the duration from catheter insertion to delivery, and labor and neonatal outcomes did not differ significantly between the groups. Paracetamol use prior to catheter balloon insertion was associated with reduced VAS score and reduced analgesic use after catheter balloon insertion, and improved maternal mobility compared with placebo