Comparison of the Effect of Intravenous Tranexamic Acid and Sublingual Misoprostol on Reducing Bleeding After Cesarean Section: A Double-Blind Randomized Clinical Trial

Tranexamic acid for preventing postpartum haemorrhage after vaginal birth

RATIONALE

Postpartum haemorrhage (PPH) is common and potentially life-threatening. The antifibrinolytic drug tranexamic acid (TXA) is thought to be effective for treating PPH. There is growing interest in whether TXA is effective for preventing PPH after vaginal birth. In randomised controlled trials (RCTs), TXA has been associated with increased risk of seizures and unexplained increased mortality when given more than three hours after traumatic bleeding. Reliable evidence on the effects, cost-effectiveness and safety of prophylactic TXA is required before considering widespread use. This review updates one published in 2015.

OBJECTIVES

To assess the effects of TXA for preventing PPH compared to placebo or no treatment (with or without uterotonic co-treatment) in women following vaginal birth.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL, and WHO ICTRP (to 6 September 2024). We also searched reference lists of retrieved studies.

ELIGIBILITY CRITERIA

We included RCTs evaluating TXA alone or in addition to standard care (uterotonics) for preventing PPH following vaginal birth. For this update, we required trials to be prospectively registered (before participant recruitment), and we applied a trustworthiness checklist.

OUTCOMES

Critical outcomes were blood loss ≥ 500 mL and blood loss ≥ 1000 mL. Important outcomes included maternal death, severe morbidity, blood transfusion, receipt of additional surgical interventions to control PPH, thromboembolic events, receipt of additional uterotonics, hysterectomy, and maternal satisfaction.

RISK OF BIAS

We used the Cochrane risk of bias tool (RoB 1) to assess the risk of bias in the studies.

SYNTHESIS METHODS

Two review authors independently selected trials, extracted data, assessed risk of bias, and assessed trial trustworthiness. We used random-effects meta-analysis to combine data. We assessed the certainty of the evidence using GRADE.

INCLUDED STUDIES

We included three RCTs with 18,974 participants in total. The trials were conducted in both high- and low-resource settings and involved participants at both low and high risk of PPH. The trials compared intravenous TXA (1 g) and standard care versus placebo (saline) and standard care. After applying our trustworthiness checklist, we did not include any of the 12 trials in the previous version of this review.

SYNTHESIS OF RESULTS

Prophylactic tranexamic acid in addition to standard care compared to placebo in addition to standard care TXA results in little to no difference in blood loss ≥ 500 mL (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.81 to 1.06; 2 studies, 18,897 participants; 5 fewer per 1000, 95% CI 15 fewer to 5 more; high-certainty evidence). TXA likely results in little to no difference in blood loss ≥ 1000 mL (RR 0.86, 95% CI 0.69 to 1.07; 2 studies, 18,897 participants; 3 fewer per 1000, 95% CI 6 fewer to 1 more; moderate-certainty evidence). TXA likely results in little to no difference in severe morbidity (RR 0.88, 95% CI 0.69 to 1.12; 1 study, 15,066 participants; 2 fewer per 1000, 95% CI 6 fewer to 2 more; moderate-certainty evidence). TXA results in little to no difference in receipt of blood transfusion (RR 1.00, 95% CI 0.95 to 1.06; 3 studies, 18,972 participants; 0 fewer per 1000, 95% CI 10 fewer to 12 more; high-certainty evidence). TXA may result in little to no difference in receipt of additional surgical interventions to control PPH (RR 0.63, 95% CI 0.32 to 1.23; 2 studies, 18,972 participants; 1 fewer per 1000, 95% CI 2 fewer to 1 more; low-certainty evidence). In women with anaemia, TXA results in little to no difference in receipt of additional uterotonics (RR 1.02, 95% CI 0.94 to 1.10; 1 study, 15,066 participants; 3 more women per 1000, 95% CI 8 fewer to 24 more; high-certainty evidence). In women with no anaemia, TXA results in a slight reduction in receipt of additional uterotonics (RR 0.75, 95% CI 0.61 to 0.92; 1 study, 3891 participants; 24 fewer women per 1000, 95% CI 38 fewer to 8 fewer; high-certainty evidence). TXA likely results in little to no difference in maternal satisfaction. The evidence is very uncertain about the effect of TXA on maternal death, thromboembolic events, and hysterectomy (very low-certainty evidence): maternal death (RR 0.99, 95% CI 0.39 to 2.49; 2 studies, 15,081 participants; 0 fewer per 1000, 95% CI 1 fewer to 2 more); thromboembolic events (RR 0.25, 95% CI 0.03 to 2.24; 3 studies, 18,774 participants; 3 fewer women per 10,000, 95% CI 4 fewer to 5 more); hysterectomy (RR 0.89, 95% CI 0.36 to 2.19; 1 study, 15,066 participants; 1 fewer women per 10,000, 95% CI 9 fewer to 16 more).

AUTHORS' CONCLUSIONS

Adding prophylactic TXA to standard care of women during vaginal birth makes little to no difference to blood loss ≥ 500 mL and likely makes little to no difference to blood loss ≥ 1000 mL or the risk of severe morbidity, compared to placebo and standard care. TXA may result in little to no difference in additional surgical interventions to control PPH and results in little to no difference in blood transfusions. One trial found that TXA reduced the use of additional uterotonics in women without anaemia, whereas the largest trial found little to no difference in the use of additional uterotonics in women with anaemia. Although there were very few serious adverse events reported, the evidence is insufficient to draw conclusions about the effect of TXA on maternal death, thromboembolic events, hysterectomy, or seizures. TXA likely results in little to no difference in maternal satisfaction. These findings are based mainly on two large trials. In the smaller of these, less than 30% of study participants were at high risk of PPH. In the largest trial, all participants had moderate to severe anaemia. Those making decisions about routine administration of prophylactic TXA for all women having vaginal births should consider that current evidence does not show a benefit of TXA for blood loss outcomes and related morbidity, and the evidence is very uncertain about serious adverse events.

FUNDING

This review was partially funded by the World Health Organization (WHO).

REGISTRATION

Protocol (2009) DOI: 10.1002/14651858.CD007872 Original review (2010) DOI: 10.1002/14651858.CD007872.pub2 Review update (2015) DOI: 10.1002/14651858.CD007872.pub3.

Tranexamic acid for preventing postpartum haemorrhage after caesarean section

RATIONALE

Postpartum haemorrhage (PPH) is common and potentially life-threatening. The antifibrinolytic drug tranexamic acid (TXA) is recommended for treating PPH; it reduces the risk of death from haemorrhage by one-third when given soon after bleeding onset, but not overall risk of death. Interest in whether TXA may be effective in preventing PPH is growing. Evidence indicates that TXA given more than three hours after injury to bleeding trauma patients increases mortality. Potential harm becomes critical in prophylactic use of TXA. Reliable evidence of the effect and safety profile of TXA is required before widespread prophylactic use can be considered.

OBJECTIVES

To assess the effects of TXA for preventing PPH compared to placebo or no treatment (with or without uterotonic co-treatment) in women during caesarean birth.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and WHO ICTRP to 20 February 2024 and searched reference lists of retrieved studies.

ELIGIBILITY CRITERIA

We included randomised controlled trials (RCTs) evaluating the use of TXA alone or plus uterotonics during caesarean birth for preventing PPH. Trials needed to be prospectively registered (i.e. before starting recruitment). We applied a trustworthiness checklist.

OUTCOMES

The critical outcome was blood loss ≥ 1000 mL, measured using estimated or calculated methods. Important outcomes included maternal death, severe morbidity, blood transfusion, the use of additional surgical interventions to control PPH, thromboembolic events, use of additional uterotonics, hysterectomy, maternal satisfaction, and breastfeeding at discharge.

RISK OF BIAS

We assessed risk of bias in the included studies using Cochrane's RoB 1 tool.

SYNTHESIS METHODS

Two review authors independently selected trials, extracted data, and assessed risk of bias and trial trustworthiness. We pooled data using random-effects meta-analysis. We assessed the certainty of the evidence using GRADE.

INCLUDED STUDIES

We included six RCTs with 15,981 participants. All 12 trials in the previous version of this review were not included after review of trial registrations and trustworthiness checklists. Most included studies involved women at low risk of PPH and were conducted in high-resource settings.

SYNTHESIS OF RESULTS

Prophylactic TXA in addition to standard care compared to placebo in addition to standard care or standard care alone TXA results in little to no difference in estimated blood loss ≥ 1000 mL (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.79 to 1.11; 4 RCTs; n = 13,042; high certainty evidence), resulting in 8 fewer per 1000 women having estimated blood loss ≥ 1000 mL (from 30 fewer to 16 more). TXA likely results in a slight reduction in calculated blood loss ≥ 1000 mL (RR 0.83, 95% CI 0.76 to 0.92; 2 RCTs; n = 4327; moderate certainty evidence), resulting in 53 fewer per 1000 having calculated blood loss ≥ 1000 mL (from 75 fewer to 25 fewer). The evidence is very uncertain about the effect of TXA on maternal death (one event in placebo group, none in TXA group). No trials measured severe morbidity. TXA likely results in little to no difference in blood transfusion (RR 0.88, 95% CI 0.72 to 1.08; 5 RCTs; n = 15,740; moderate certainty evidence), resulting in 4 fewer per 1000 women requiring a blood transfusion (from 10 fewer to 3 more). TXA results in little to no difference in additional surgical interventions to control PPH (RR 1.02, 95% CI 0.86 to 1.22; 4 RCTs; n = 15,631; high certainty evidence), resulting in 1 more per 1000 women requiring additional surgical intervention (from 4 fewer to 7 more). The evidence is very uncertain about the effect of TXA on thromboembolic events (RR 1.40, 95% CI 0.22 to 8.90; 4 RCTs; n = 14,480; very low certainty evidence), resulting in 1 more per 1000 women having a thromboembolic event (from 2 fewer to 17 more). TXA results in little to no difference in the need for additional uterotonics (RR 0.88, 95% CI 0.78 to 1.00; 4 RCTs; n = 15,728; high certainty evidence), resulting in 15 fewer per 1000 women requiring additional uterotonics (from 27 fewer to 0 fewer). The evidence is very uncertain about the effect of TXA on hysterectomy (RR 0.80, 95% CI 0.20 to 3.29; 2 RCTs; n = 4546; very low certainty evidence), resulting in 3 fewer per 10,000 women requiring a hysterectomy (from 11 fewer to 31 more). One trial measuring maternal satisfaction reported no difference between groups at day two postpartum. No data were available on breastfeeding. Overall, studies had low risk of bias. We downgraded the certainty of evidence mainly for imprecision.

AUTHORS' CONCLUSIONS

Prophylactic TXA in addition to standard care during caesarean birth results in little to no difference in estimated blood loss ≥ 1000 mL and likely results in a slight reduction in calculated blood loss ≥ 1000 mL compared to placebo. There were no data for severe morbidity due to PPH. Event rates for further interventions to control PPH were low and similar across groups. Prophylactic TXA thus results in little to no difference between groups for additional surgical interventions (32 versus 31 per 1000), and likely results in little to no difference between groups for blood transfusions (31 versus 36 per 1000) and use of additional uterotonics (107 versus 121 per 1000). There were very few events for the outcomes maternal death (1 in placebo group), thromboembolic events (2 versus 3 per 1000), and hysterectomy (1 per 1000 in each group). Evidence for these serious adverse events is therefore very uncertain. Decisions about implementing routine prophylactic TXA during caesarean birth should not only consider outcomes related to blood loss, but also the relatively low rates of PPH morbidity and uncertainty of serious adverse events. Most studies included women at low risk of PPH, thereby precluding any conclusions about women at high risk of PPH. Cost associated with routine use of an additional drug for all caesarean births needs to be considered.

FUNDING

This Cochrane review was funded in part by the World Health Organization.

REGISTRATION

The published protocol and updates to the review can be accessed: Protocol (2009) DOI: 10.1002/14651858.CD007872 Original Review (2010) DOI: 10.1002/14651858.CD007872.pub2 Review Update (2015) DOI: 10.1002/14651858.CD007872.pub3.

Tranexamic acid versus misoprostol for management of postpartum hemorrhage: A systematic review and meta-analysis of randomized controlled trials

AIM

To conduct the first-ever systematic review and meta-analysis of randomized controlled trials (RCTs) on the antihemorrhagic utility and safety of tranexamic acid (TXA) versus misoprostol for management (prevention and/or treatment) of postpartum hemorrhage (PPH).

METHODS

Six databases were screened from inception until May 2023 and updated in September 2023. The RCTs were assessed for quality according to the Cochrane's risk of bias tool. The endpoints were summarized as mean difference (MD) or risk ratio (RR) with 95% confidence interval (CI) in a random-effects model.

RESULTS

Ten RCTs with 2121 patients (TXA = 1061 and misoprostol = 1060) were analyzed. There was no significant difference between TXA and misoprostol groups regarding the mean intraoperative blood loss (n = 9 RCTs, MD = 17.32 ml, 95% CI [-40.43, 75.07], p = 0.56), mean change in hemoglobin (n = 6 RCTs, MD = 0.11 mg/dl, 95% CI [-0.1, 0.31], p = 0.30), mean hospital stay (n = 2 RCTs, MD = -0.3 day, 95% CI [-0.61, 0.01], p = 0.06), blood transfusion rate (n = 4 RCTs, RR = 0.49, 95% CI [0.16, 1.47], p = 0.2), and rate of additional uterotonic agents (n = 4 RCTs, RR = 1.05, 95% CI [0.72, 1.53], p = 0.81). Leave-one-out sensitivity analysis showed robustness of the results, and there was no evidence of publication bias. Regarding safety endpoints, there was no significant difference between both groups regarding the rates of minor side effects, such as diarrhea, fever, nausea, and vomiting. No patient developed thromboembolic events in the TXA group.

CONCLUSION

There was no significant antihemorrhagic efficacy between adjunct TXA and misoprostol for the management of PPH. The safety profile was comparable between both agents.

WITHDRAWN: The Effect of Preoperative Intravenous Tranexamic Acid Versus Rectal Misoprostol in Reducing Blood Loss During and After Elective Cesarean Delivery in Primigravida: A Double-Blinded, Randomized, Comparative-Placebo Trial

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Tranexamic acid for the prevention of blood loss after cesarean section: an updated systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Tranexamic acid is a cost-effective intervention for the prevention of postpartum hemorrhage among women who undergo cesarean delivery, but the evidence to support its use is conflicting. We conducted this meta-analysis to evaluate the efficacy and safety of tranexamic acid in low- and high-risk cesarean deliveries.

DATA SOURCES

We searched MEDLINE (via PubMed), Embase, the Cochrane Library, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform portal from inception to April 2022 (updated October 2022 and February 2023) with no language restrictions. In addition, grey literature sources were also explored.

STUDY ELIGIBILITY CRITERIA

All randomized controlled trials that investigated the prophylactic use of intravenous tranexamic acid in addition to standard uterotonic agents among women who underwent cesarean deliveries in comparison with a placebo, standard treatment, or prostaglandins were included in this meta-analysis.

METHODS

We used the revised Cochrane Risk of Bias tool (RoB 2.0) to assess the quality of the included randomized controlled trials. RevMan 5.4 was used to conduct all statistical analyses using a random-effects model.

RESULTS

We included 50 randomized controlled trials (6 in only high-risk patients and 2 with prostaglandins as the comparator) that evaluated tranexamic acid in our meta-analysis. Tranexamic acid reduced the risk for blood loss >1000 mL, the mean total blood loss, and the need for blood transfusion in both low- and high-risk patients. Tranexamic acid was associated with a beneficial effect in the secondary outcomes, including a decline in hemoglobin levels and the need for additional uterotonic agents. Tranexamic acid increased the risk for nonthromboembolic adverse events but, based on limited data, did not increase the incidence of thromboembolic events. The administration of tranexamic acid before skin incision, but not after cord clamping, was associated with a large benefit. The quality of evidence was rated as low to very low for outcomes in the low-risk population and moderate for most outcomes in the high-risk subgroup.

CONCLUSION

Tranexamic acid may reduce the risk for blood loss in cesarean deliveries with a higher benefit observed in high-risk patients, but the lack of high-quality evidence precludes any strong conclusions. The administration of tranexamic acid before skin incision, but not after cord clamping, was associated with a large benefit. Additional studies, especially in the high-risk population and focused on evaluating the timing of tranexamic acid administration, are needed to confirm or refute these findings.

Tranexamic acid for the prevention of postpartum hemorrhage in women undergoing cesarean delivery: an updated meta-analysis

OBJECTIVE

This study aimed to assess the efficacy and safety of prophylactic tranexamic acid administration vs standard uterotonic agents alone among women undergoing cesarean delivery.

DATA SOURCES

MEDLINE, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and Google Scholar were systematically searched from inception to June 30, 2021.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials comparing intravenous tranexamic acid administration with placebo in women undergoing cesarean delivery and receiving standard prophylactic uterotonic agents were held eligible.

STUDY APPRAISAL AND SYNTHESIS METHODS

The risk of bias of individual studies was appraised with the Risk of Bias 2 tool. Meta-analysis was conducted by fitting random-effects models using restricted maximum likelihood. Subgroup analysis was performed on the basis of country, protocol availability, double-blinding, risk of bias, sample size, and tranexamic acid dose. A 1-stage meta-analysis was performed as a sensitivity analysis. The credibility of outcomes was appraised with the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Overall, 36 studies with 10,659 women were included. Tranexamic acid administration was associated with significantly lower total blood loss (mean difference, -189.44 mL; 95% confidence intervals, -218.63 to -160.25), lower hemoglobin drop (mean difference, 8.22%; 95% confidence interval, 5.54-10.90), decreased risk of blood loss of >1000 mL (odds ratio, 0.37; 95% confidence interval, 0.22-0.60), transfusion requirement (odds ratio, 0.41; 95% confidence interval, 0.26-0.65), and need of additional uterotonics (odds ratio, 0.36; 95% confidence interval, 0.25-0.52). Subgroup analysis indicated a greater effect of tranexamic acid on total blood loss reduction in low-middle income countries. The outcomes remained stable by separately evaluating women at low bleeding risk. The 1-stage meta-analysis demonstrated similar outcomes with the primary analysis. The quality of evidence was judged to be moderate regarding total blood loss and hemoglobin percentage change and low for the other outcomes.

CONCLUSION

This meta-analysis suggested that prophylactic tranexamic acid administration is effective among women undergoing cesarean delivery in lowering postpartum blood loss and limiting hemoglobin drop. Further research is needed to test its efficacy in high-risk populations and verify its safety profile.

Rectal vs. sublingual misoprostol in cesarean section: Three‑arm, randomized clinical trial

BACKGROUND

Misoprostol is a myometrial stimulant with uterotonic properties and can be administered rectally, vaginally, or sublingually. Numerous studies have investigated the effect of misoprostol on the prevention and treatment of PPH (postpartum hemorrhage) after vaginal delivery, but its use to control PPH during cesarean section has not been widely studied.

METHODS

In this clinical trial study, 180 pregnant women who were candidates for cesarean section were included in the study. They were divided into 3 groups of 60 people (sublingual misoprostol group, rectal misoprostol group, control group). In all three groups, the volume of blood lost was recorded in the checklist at the end of surgery. Data were entered into SPSS software and analyzed.

RESULTS

The mean bleeding in the control group was 225.4±63.9, while it was 137.9±33.8 and 118.9±28.5 in the sublingual misoprostol group and rectal misoprostol group, respectively. We had significantly more bleeding in the control group (p<0.001) compared to the other two groups.

CONCLUSION

These results confirm the positive effect of misoprostol in reducing bleeding and show the superiority of using rectal misoprostol compared to other methods of reducing bleeding during cesarean section.