Tranexamic acid, as an adjunct to oxytocin prophylaxis, in the prevention of postpartum haemorrhage in women undergoing elective caesarean section: A single-centre double-blind randomised controlled trial

Abstract

Objective: To evaluate the effectiveness of tranexamic acid (TXA) in reducing blood loss during elective caesarean sections in women with and without risk factors for postpartum haemorrhage (PPH). Design: A double-blind, randomised placebo-controlled trial. Setting: An academic tertiary referral centre in Singapore. Population: Multiethnic women aged 21 years or older undergoing elective caesarean section. Methods: Randomisation to intravenous TXA or normal saline (placebo) 10 minutes before skin incision. Main outcome measures: Calculated estimated blood loss (cEBL), derived from blood volume and haematocrit levels. Results: Between June 2020 and October 2021, 200 women were randomised to the placebo or TXA groups. Women who received prophylactic TXA had a significantly lower mean cEBL compared with those receiving placebo (adjusted mean difference −126.4 mL, 95% CI −243.7 to −9.1, p = 0.035). The effect was greatest in those at high risk for PPH, with a reduction in cEBL (mean difference −279.6 mL, 95% CI −454.8 to −104.3, p = 0.002) and a lower risk of cEBL ≥500 mL (risk ratio [RR] 0.54, 95% CI 0.36–0.83, p = 0.007) and cEBL ≥1000 mL (RR 0.44, 95% CI 0.20–0.98, p = 0.016). Subgroup analysis showed benefit for women with preoperative haemoglobin <10.5 g/dL (mean difference −281.9 mL, 95% CI −515.0 to −48.8, p = 0.019). There was no significant difference in need for additional medical or surgical interventions. There were no maternal or neonatal adverse outcomes. Conclusion: Prophylactic TXA should be considered in women with risk factors for PPH, and those most likely to benefit are those with preoperative haemoglobin <10.5 g/dL.