The effect of prophylactic oral tranexamic acid plus buccal misoprostol on blood loss after vaginal delivery: a randomized controlled trial

Prophylactic tranexamic acid during myomectomy: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To conduct a systematic review and meta-analysis of randomized controlled trials on the clinical efficacy and safety of prophylactic tranexamic acid (TXA) versus control (normal saline/no treatment) during myomectomy.

METHODS

Six databases were screened from inception until 21-February-2022. The eligible studies were assessed for risk of bias. The outcomes were summarized as mean difference (MD) and risk ratio (RR) with 95% confidence intervals (CI) in a random-effects model.

RESULTS

Seven studies, comprising eight arms and 571 patients (TXA = 304 patients, control = 267 patients) were analyzed. The included studies had an overall low risk of bias. The mean intraoperative blood loss (MD = -224.34 ml, 95% CI [-303.06, -145.61], p < 0.001), mean postoperative blood loss, and mean total blood loss were significantly reduced in favor of the prophylactic TXA group. Additionally, the mean postoperative hemoglobin (MD = 0.4 mg/dl, 95% CI [0.11, 0.68], p = 0.006) and mean postoperative hematocrit levels were significantly higher in favor of the prophylactic TXA group. While the mean hospital stay was significantly reduced in favor of the prophylactic TXA group (MD = -0.39 d, 95% [-0.74, -0.04], p = 0.03), there was no significant difference between both groups regarding the mean operation time and rate of blood transfusion. None of the participants in both groups developed any incidence of thromboembolic events. The rate of nausea was significantly higher in disfavor of the prophylactic TXA group (RR = 2.68, 95% CI [1.11, 6.43], p = 0.03).

CONCLUSION

Among patients undergoing myomectomy, prophylactic TXA was largely safe and linked to substantial reductions in perioperative blood loss and related morbidities.

A double-blind, randomized controlled trial to explore oral tranexamic acid as adjunct for the treatment for postpartum hemorrhage

BACKGROUND

Oral tranexamic acid (TXA), if effective in reducing blood loss after delivery for women experiencing primary PPH, could be administered where parenteral administration is not feasible. This trial assessed the efficacy, safety, and acceptability of oral TXA when used as an adjunct to sublingual misoprostol to treat postpartum hemorrhage (PPH) following vaginal delivery.

METHODS

From October 2016 to January 2018, women presenting at four hospitals in Senegal and Vietnam for vaginal delivery were screened for enrollment in the trial. Women diagnosed with postpartum hemorrhage (defined as blood loss ≥700 ml) were randomized to receive either oral TXA (1950 mg) or placebo in addition to 800 mcg sublingual misoprostol. Postpartum blood loss was measured using a calibrated drape. Blood loss for all PPH cases was recorded for 2 h after administration of the drugs. The primary outcome measure was the proportion of women with bleeding controlled with the trial regimen without recourse to further treatment. Secondary outcomes including the rate of severe PPH, mean/median blood loss, use of additional uterotonics and/or interventions side effects, and acceptability were also recorded.

RESULTS

Of the 258 women who received treatment for PPH, 128 received placebo and misoprostol and 130 received TXA and misoprostol. The proportion of women who had active bleeding controlled with trial drugs alone and no additional interventions was similar in both groups: 77(60.2%) placebo; 74 (56.9%) TXA, p = 0.59). Use of other interventions to control bleeding, including uterotonics, did not differ significantly between groups. Median blood loss at PPH diagnosis was 700 ml in both groups. Uterine atony alone or in addition to another cause contributed to over 90% of PPH cases reported (92.2% placebo vs. 91.5% TXA), other causes included perineal and cervical lacerations and retained placenta. Reports of side effects and acceptability were similar in the two groups.

CONCLUSION

Adjunct use of oral TXA with misoprostol to treat PPH resulted in similar clinical and acceptability outcomes when compared to treatment with misoprostol alone.

TRIAL REGISTRATION

This trial was registered with ClinicalTrials.gov, number NCT02805426. Registered on 3 September 2016.

Postpartum haemorrhage (PPH) rates in randomized trials of PPH prophylactic interventions and the effect of underlying participant PPH risk: a meta-analysis

Background

Postpartum haemorrhage (PPH) remains a leading cause of maternal mortality. Many trials assessing interventions to prevent PPH base their data on low risk women. It is important to consider the impact data collection methods may have on these results. This review aims to assess trials of PPH prophylaxis by grading trials according to the degree of risk status of the population enrolled in these trials and identify differences in the PPH rates of low risk and high risk populations.

Methods

Systematic review and meta-analysis using a random-effects model. Trials were identified through CENTRAL. Trials were assessed for eligibility then graded according to antenatal risk factors and method of birth into five grades. The main outcomes were overall trial rate of minor PPH (blood loss ≥500 ml) and major PPH (> 1000 ml) and method of determining blood loss (estimated/measured).

Results

There was no relationship between minor or major PPH rate and risk grade (Kruskal-Wallis: minor - T = 0.92, p = 0.82; major - T = 0.91, p = 0.92). There was no difference in minor or major PPH rates when comparing estimation or measurement methods (Mann-Whitney: minor - U = 67, p = 0.75; major - U = 35, p = 0.72). There was however a correlation between % operative births and minor PPH rate, but not major PPH (Spearman r = 0.32 v. Spearman r = 0.098).

Conclusions

Using data from trials using low risk women to generalise best practice guidelines might not be appropriate for all births, particularly complex births. Although complex births contribute disproportionately to PPH rates, this review showed they are often underrepresented in trials. Despite this, there was no difference in reported PPH rates between studies conducted in high and low risk groups. Method of birth was shown to be an important risk factor for minor PPH and may be a better predictor of PPH than antenatal risk factors. Women with operative births are often excluded from trials meaning a lack of data supporting interventions in these women. More focus on complex births is needed to ensure the evidence base is relevant to the target population.

Placenta percreta evaluated by MRI: correlation with maternal morbidity

PURPOSE

The purpose of this study was to evaluate the capability of MRI in depicting the topography of placenta percreta (PP) and to further explore the correlation between invasion topography and maternal outcomes.

METHODS

55 patients with histologically or surgically confirmed PP were included in this retrospective study. Two senior radiologists evaluated the topography of PP based on MR images: the invasion topography was depicted as S1, S2, parametrial, bladder, and cervical invasion. The correlation between invasion topography and maternal outcomes was analyzed using Chi-square statistic.

RESULTS

MRI showed high sensitivity and specificity in delineating the invasion topography of PP (ranging from 87.5 to 100%). MRI had 100% specificity for predicting the parametrial, bladder, and cervical invasion. The rate of cesarean hysterectomy, ureteral injuries and ICU administration, and the amount of blood transfusions in PP with S2 invasion were higher than S1 invasion (P < 0.05). In addition, all patients with bladder invasion (8/8) received partial bladder resection by urologists. All the patients with S2 parametrial invasion (12/12) or cervical invasion (9/9) underwent cesarean hysterectomy.

CONCLUSION

MRI was capable in predicting the invasion topography of PP patients. Moreover, PP patients with S2, parametrial, bladder or cervical invasion had more severe maternal morbidity.

Tranexamic acid for postpartum hemorrhage prevention in vaginal delivery: A meta-analysis

BACKGROUND

Tranexamic acid (TA) has been demonstrated to reduce blood loss and the incidences of postpartum hemorrhage (PPH) during caesarean sections. We compared the clinical efficacy of TA administration on vaginal deliveries with recently published papers.

METHODS

Electronic databases of PubMed, Cochrane Library, Embase and Chinese CNKI (Chinese database) and Wanfang were searched through November 2019.The randomized controlled trials were selected between TA and control groups. The relevant studies included four trials with a total of 4579 patients.

RESULTS

Patients treated with TA had a reduction in total blood loss (P = .009), lower postoperative blood loss (P < .00001), a reduced number of PPH (P = .02). However, the occurrence of nausea or/and vomiting is higher in the TA group (the incidence of nausea or vomiting [P < .00001], nausea [P < .00001] and vomiting [P < .00001]).

CONCLUSION

TA resulted in fewer occurrence rates of PPH, and no significant increase in occurrences of dizziness or photopsia, but higher incidence of vomiting and nausea.

Uterotonic agents for preventing postpartum haemorrhage: a network meta-analysis

BACKGROUND

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Prophylactic uterotonic agents can prevent PPH, and are routinely recommended. The current World Health Organization (WHO) recommendation for preventing PPH is 10 IU (international units) of intramuscular or intravenous oxytocin. There are several uterotonic agents for preventing PPH but there is still uncertainty about which agent is most effective with the least side effects. This is an update of a Cochrane Review which was first published in April 2018 and was updated to incorporate results from a recent large WHO trial.

OBJECTIVES

To identify the most effective uterotonic agent(s) to prevent PPH with the least side effects, and generate a ranking according to their effectiveness and side-effect profile.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (24 May 2018), and reference lists of retrieved studies.

SELECTION CRITERIA

All randomised controlled trials or cluster-randomised trials comparing the effectiveness and side effects of uterotonic agents with other uterotonic agents, placebo or no treatment for preventing PPH were eligible for inclusion. Quasi-randomised trials were excluded. Randomised trials published only as abstracts were eligible if sufficient information could be retrieved.

DATA COLLECTION AND ANALYSIS

At least three review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We estimated the relative effects and rankings for preventing PPH ≥ 500 mL and PPH ≥ 1000 mL as primary outcomes. Secondary outcomes included blood loss and related outcomes, morbidity outcomes, maternal well-being and satisfaction and side effects. Primary outcomes were also reported for pre-specified subgroups, stratifying by mode of birth, prior risk of PPH, healthcare setting, dosage, regimen and route of administration. We performed pairwise meta-analyses and network meta-analysis to determine the relative effects and rankings of all available agents.

MAIN RESULTS

The network meta-analysis included 196 trials (135,559 women) involving seven uterotonic agents and placebo or no treatment, conducted across 53 countries (including high-, middle- and low-income countries). Most trials were performed in a hospital setting (187/196, 95.4%) with women undergoing a vaginal birth (71.5%, 140/196).Relative effects from the network meta-analysis suggested that all agents were effective for preventing PPH ≥ 500 mL when compared with placebo or no treatment. The three highest ranked uterotonic agents for prevention of PPH ≥ 500 mL were ergometrine plus oxytocin combination, misoprostol plus oxytocin combination and carbetocin. There is evidence that ergometrine plus oxytocin (RR 0.70, 95% CI 0.59 to 0.84, moderate certainty), carbetocin (RR 0.72, 95% CI 0.56 to 0.93, moderate certainty) and misoprostol plus oxytocin (RR 0.70, 95% CI 0.58 to 0.86, low certainty) may reduce PPH ≥ 500 mL compared with oxytocin. Low-certainty evidence suggests that misoprostol, injectable prostaglandins, and ergometrine may make little or no difference to this outcome compared with oxytocin.All agents except ergometrine and injectable prostaglandins were effective for preventing PPH ≥ 1000 mL when compared with placebo or no treatment. High-certainty evidence suggests that ergometrine plus oxytocin (RR 0.83, 95% CI 0.66 to 1.03) and misoprostol plus oxytocin (RR 0.88, 95% CI 0.70 to 1.11) make little or no difference in the outcome of PPH ≥ 1000 mL compared with oxytocin. Low-certainty evidence suggests that ergometrine may make little or no difference to this outcome compared with oxytocin meanwhile the evidence on carbetocin was of very low certainty. High-certainty evidence suggests that misoprostol is less effective in preventing PPH ≥ 1000 mL when compared with oxytocin (RR 1.19, 95% CI 1.01 to 1.42). Despite the comparable relative treatment effects between all uterotonics (except misoprostol) and oxytocin, ergometrine plus oxytocin, misoprostol plus oxytocin combinations and carbetocin were the highest ranked agents for PPH ≥ 1000 mL.Misoprostol plus oxytocin reduces the use of additional uterotonics (RR 0.56, 95% CI 0.42 to 0.73, high certainty) and probably also reduces the risk of blood transfusion (RR 0.51, 95% CI 0.37 to 0.70, moderate certainty) when compared with oxytocin. Carbetocin, injectable prostaglandins and ergometrine plus oxytocin may also reduce the use of additional uterotonics but the certainty of the evidence is low. No meaningful differences could be detected between all agents for maternal deaths or severe morbidity as these outcomes were rare in the included randomised trials where they were reported.The two combination regimens were associated with important side effects. When compared with oxytocin, misoprostol plus oxytocin combination increases the likelihood of vomiting (RR 2.11, 95% CI 1.39 to 3.18, high certainty) and fever (RR 3.14, 95% CI 2.20 to 4.49, moderate certainty). Ergometrine plus oxytocin increases the likelihood of vomiting (RR 2.93, 95% CI 2.08 to 4.13, moderate certainty) and may make little or no difference to the risk of hypertension, however absolute effects varied considerably and the certainty of the evidence was low for this outcome.Subgroup analyses did not reveal important subgroup differences by mode of birth (caesarean versus vaginal birth), setting (hospital versus community), risk of PPH (high versus low risk for PPH), dose of misoprostol (≥ 600 mcg versus < 600 mcg) and regimen of oxytocin (bolus versus bolus plus infusion versus infusion only).

AUTHORS' CONCLUSIONS

All agents were generally effective for preventing PPH when compared with placebo or no treatment. Ergometrine plus oxytocin combination, carbetocin, and misoprostol plus oxytocin combination may have some additional desirable effects compared with the current standard oxytocin. The two combination regimens, however, are associated with significant side effects. Carbetocin may be more effective than oxytocin for some outcomes without an increase in side effects.