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.

Keywords: blood loss; caesarean section; postpartum haemorrhage; prophylaxis; tranexamic acid; transfusion; uterotonics.