The review included total of 3,271 patients enrolled in: six RCTs (994 patients), seven non-randomised observational studies (409 patients) and 22 case reports (numbers differed between the text and data tables). None of the RCTs reported adequate allocation concealment; all reported adequate randomisation, but none were blinded or reported intention-to-treat data. One of the seven non-RCT observational studies was awarded an evidence grade of 3, three were awarded a 2+, and two studies a 2-. One study was not awarded an evidence level.
Three RCTs that assessed the effects of tranexamic acid administration prior to caesarean section all reported that blood loss was significantly reduced for tranexamic acid in comparison with placebo. Studies of the early management of postpartum haemorrhage after vaginal delivery reported a lower blood loss (two RCTs) associated with tranexamic acid and a shorter duration of bleeding (one RCT) in comparison with placebo. One RCT to arrest bleeding in women with a history of miscarriage reported a significant reduction in the duration of bleeding episodes (p<0.001) in comparison with placebo. There was no significant reduction in pooled postpartum blood loss compared with placebo when tranexamic acid was given prior to caesarean section (three RCTs). This meta-analysis was associated with a significant degree of statistical heterogeneity (I2=98.7%). Adverse events reported in the RCTs included transient visual and digestive effects (one RCT), transient mild adverse events (one RCT) and nausea (one RCT). Three RCTs reported no significant maternal or neonatal adverse effects.
The review reported data for the included non-randomised observational studies and case reports. In these studies tranexamic acid was found to show beneficial effects in preventing and treating bleeding. Adverse events reported in the studies included two cases of pulmonary embolism; however, the possible involvement of tranexamic acid was not proven.