Postpartum Hemorrhage Reduction With Oral Tranexamic Acid: a Clinical Trial

Background Severe PPH is the leading cause of maternal death worldwide especially in developing countries. Preventing PPH before onset is of key importance because once bleeding starts it is difficult to control.Tranexamic acid (TA) is a well-established medication for treatment and prevention of heavy bleeding. Oral forms of TA are available over the counter in many settings. The effect of oral treatment in vaginal deliveries has however been little studied and is a stated research priority by the WHO. Oral TA is low-cost, stable at room temperature and easy to administer which makes it especially applicable to both low resource delivery settings and home- births.To prevent PPH, a therapeutic serum concentration of TA should coincide with the period immediately after delivery of the child, when the risk of PPH is greatest, meaning that TA should optimally be administered during the latter part of active labor.

The premises of the RCT are the following:

1. The effect of oral prophylactic TA on rate of PPH is insufficiently known 2. If oral TA is effective in preventing PPH, routine administration could reduce maternal morbidity significantly at low expense.

Methods Study population and inclusion criteria The study will include 1000 women planned for vaginal delivery at three study sites in Sweden (n=500) and two study sites in South Africa (n=500) during the period September 2023 to December 2026. Enrolled women will be ≥18 years, ≥36 gestational weeks, and planned for vaginal delivery. Women with known bleeding disorders, known allergy to TA, ongoing treatment for venous thrombosis, or inability to make an informed consent will be ineligible.

Setting and duration: The study will take place between September 2023 and December 2026 at three study sites in Sweden as well as Mowbray Maternity Hospital and Khayelitsha District Hospital in South Africa.

Recruitment and randomization We will recruit women during a routine or planned antenatal visit after 35 gestational weeks, or after admission to the delivery ward during the latency phase of labor or the early stages of labor.

Randomization will occur after a woman has been admitted to the labor ward with spontaneous onset of labor. Participants will be randomized to receive either 20 ml of the investigational medicinal product (TA) or 20ml of a placebo solution. The randomization sequence will be computer-generated by KTA (Karolinska Clinical Trial Alliance) and flasks with the IMP/placebo will be marked according to this sequence. Randomization will be 1:1 in permuted blocks of 10 to allow for block-sized deliveries to study sites. The placebo will be developed and manufactured by Apotek Produktion och Laboratorier (APL), Sweden, who will also supply the TA. Placebo and IMP flasks, in their randomization sequence will be transported in a temperature-validated delivery to a central laboratory in Cape Town through World Courier who specialises in research related distributions.

Intervention Our intervention consists of the oral self-intake of either 20 ml (2g) of oral solution of TA, 20 ml of placebo equivalent in appearance, odor and taste to the IMP, when the cervix is fully dilated.

Primary endpoints Weight-estimated rate of PPH (≥500ml)

Secondary endpoints Pre-postpartum Hb difference (g/L) ≥10 units Weight-estimated rate of severe PPH (≥1000ml) Mean blood loss (ml) Mean pre-postpartum Hb decrease (units Rate of blood transfusion (%) Feasibility (adherence to protocol) Acceptability of the treatment among participants and providers Thromboembolism up to 6 weeks postpartum

Study procedures Participants will experience three study procedures that would not necessarily occur had they not taken part in the study but all of which form part of routine care.

1. A blood sample (hemoglobin, EVF, MCV, MCH, MCHC, LPC, TPC) taken at admission 2. The oral intake of 20 ml IMP/placebo at full cervical dilatation 3. Weighing of total blood loss (which is routine in many delivery settings) 4. A blood sample including (hemoglobin, EVF, MCV, MCH, MCHC, LPC, TPC) taken after 24 hours (or prior to discharge should discharge occur before 24 hours)

• Severe PPH [Time frame: 24 hours]
• Blood transfusion [Time frame: 72 hours]
• Mean blood loss [Time frame: 24 hours]
• Mean pre-post partal hemoglobin [Time frame: 24 hours]
• Pre-post partal hemoglobin [Time frame: 24 hours]
• Thromboembolism [Time frame: 6 weeks after delivery]
• Feasibility of intervention [Time frame: As specified in protocol]
• Acceptability for participants [Time frame: Delivery and 24 hours after delivery]
• Acceptability for providers [Time frame: Delivery and 24 hours after delivery]