Use of tranexamic acid (TXA) to reduce preterm birth and other adverse obstetrical outcomes among pregnant individuals with placenta previa: a systematic review protocol.

introductionPlacenta previa is a placental implantation pathology where the placenta overlies the internal endocervical os. Placenta previa affects approximately 4 per 1000 pregnancies and increases the risk of antepartum bleeding, emergent preterm labour and emergency caesarean sections. Currently, placenta previa is managed through expectant management. Guidelines primarily revolve around the mode and timing of delivery, in-hospital admissions and surveillance. However, the methods to prolong pregnancy have not proven to be clinically effective. Tranexamic acid (TXA), an antifibrinolytic agent, is effectively used to prevent and treat postpartum haemorrhage as well as menorrhagia, with limited adverse effect, and may prove to be an effective treatment for placenta previa. The objective of this systematic review protocol is to review and synthesise the evidence of TXA use for antepartum haemorrhage in placenta previa. METHODS AND ANALYSIS: Preliminary searches were conducted on 12 July 2022. We will search MEDLINE, EMBASE, CINAHL, Scopus and the Cochrane Central Register of Controlled Trials. Grey literature resources such as clinical trials registries (ClinicalTrials.gov and the WHO's International Clinical Trials Registry) and preprint servers (Europe PMC and Open Science Framework) will also be searched. The search terms will comprise of index headings and keyword searches related to TXA and the placenta or antepartum bleeding. Cohort and randomised and non-randomised trials will be considered. The target population is pregnant people, of any age, with placenta previa. The intervention is TXA given in the antepartum period. The main outcome of interest is preterm birth before 37 weeks, however, all perinatal outcomes will be collected. Title and abstract will be screened by two reviewers and any conflict will be discussed and evaluated by a third reviewer. The literature will be summarised in narrative form. ETHICS AND DISSEMINATION: No ethics approval is required for this protocol. Findings will be disseminated through peer-review publication, lay summaries and conference presentations. PROSPERO REGISTRATION NUMBER: CRD42022363009).