# Reviewer B

## Comments

Thank you for the opportunity to review this manuscript describing the findings of a randomised trial of tranexamic acid for postpartum bleeding in women with placenta previa giving birth by caesarean.

This is a well-conducted trial that makes an important contribution to the evidence on the effects of TXA for obstetric bleeding and is worthy of publication. The trial benefits from a robust design, prospective registration and high data completeness.

The authors clearly state that they drew on methods used in the previous TRAAP trials by Sentilhes et al, although there was no involvement of the original TRAAP trial investigators in this current trial. For this reason, we suggest that "TRAAP" is not used as part of the trial name or the name of the study group, to clearly distinguish from these earlier trials and avoid potential confusion.

The trial was powered to detect a 20% reduction in postpartum haemorrhage (defined as calculated estimated blood loss ≥ 1000 mL or red cell transfusion within 2 days after delivery), but it was not powered to detect effects on other important clinical outcomes, including those that matter most to women, such as death and surgical interventions. We therefore encourage the trialists to join the Anti-fibrinolytics Trialists Collaboration Obstetric Group and to participate in future updates of meta-analyses of trials to enable reliable estimates of the effects of TXA on these outcomes.

We would like to see more transparent and balanced reporting of the secondary outcomes in the main text. Currently, the text focuses on the outcomes showing statistically significant effects. The absence of evidence for an effect on other secondary outcomes is equally important and should be reported in a similar manner.

Assessment of women's wellbeing and satisfaction is a strength of this trial. However, these outcomes are not summarised in the main text, which instead refers readers to the supplementary material. A brief summary of these findings in the main text would improve the manuscript.

Mean calculated estimated blood loss is listed as a secondary outcome in the protocol but is not included in Table 2 and should be added or its omission explained. In addition, the time period over which outcomes were measured is reported in Table 2 for some outcomes but not for others, but should be included for all outcomes to improve clarity. Also, how was "hypovolaemic shock related to PPH" defined?

We note some errors in the CONSORT 2025 checklist (supplementary file S15). "Not applicable" is not an appropriate response for patient and public involvement; if no PPI occurred, this should be clearly stated. Also, item 22 (Participant flow, including flow diagram) should direct readers to the flow diagram in Figure 1 and the supporting text, not information in the protocol.