Abstract: Eighteen RCTs with 1250 participants met our inclusion criteria. The studies were conducted in hospital settings in low, middle and high income countries. Blood loss We found significant reductions in blood loss with the following interventions: vaginal misoprostol (2 RCTs, 89 women: MD -97.88 ml, 95% CI -125.52 to -70.24; I2 = 43%; moderate-quality evidence); intramyometrial vasopressin (3 RCTs, 128 women: MD -245.87 ml, 95% CI -434.58 to -57.16; I2 = 98%; moderate-quality evidence); intramyometrial bupivacaine plus epinephrine (1 RCT, 60 women: MD -68.60 ml, 95% CI -93.69 to -43.51; low-quality evidence); intravenous tranexamic acid (1 RCT, 100 women: MD -243 ml, 95% CI -460.02 to -25.98; low-quality evidence); gelatin-thrombin matrix (1 RCT, 50 women: MD -545.00 ml, 95% CI -593.26 to -496.74; low-quality evidence); intravenous ascorbic acid (1 RCT, 102 women: MD -411.46 ml, 95% CI -502.58 to -320.34; low-quality evidence); vaginal dinoprostone (1 RCT, 108 women: MD -131.60 ml, 95% CI -253.42 to -9.78; low-quality evidence); loop ligation of the myoma pseudocapsule (1 RCT, 70 women: MD -305.01 ml, 95% CI -354.83 to -255.19; low-quality evidence); a fibrin sealant patch (1 RCT, 70 women: MD -26.50 ml, 95% CI -44.47 to -8.53; low-quality evidence), a Foley catheter tied around the cervix (1 RCT, 93 women: MD -240.70 ml, 95% CI -359.61 to -121.79; low-quality evidence), and a polyglactin suture round both cervix and infundibulopelvic ligament (1 RCT, 28 women: MD -1870.0 ml, 95% CI -2547.16 to 1192.84; low-quality evidence). There was no good evidence of an effect on blood loss with oxytocin, morcellation or clipping of the uterine artery. Need for blood transfusion We found significant reductions in the need for blood transfusion with vasopressin (2 RCTs, 90 women: OR 0.15, 95% CI 0.03 to 0.74; I2 = 0%; moderate-quality evidence); tourniquet tied round the cervix (1 RCT, 98 women: OR 0.22, 95% CI 0.09 to 0.55; low-quality evidence); tourniquet tied round both cervix and infundibulopelvic ligament (1 RCT, 28 women: OR 0.02, 95% CI 0.00 to 0.23; low-quality evidence); gelatin-thrombin matrix (1 RCT, 100 women: OR 0.01, 95% CI 0.00 to 0.10; low-quality evidence) and dinoprostone (1 RCT, 108 women: OR 0.17, 95% CI 0.04 to 0.81; low-quality evidence), but no evidence of effect on the need for blood transfusion with misoprostol, oxytocin, tranexamic acid, ascorbic acid, loop ligation of the myoma pseudocapsule and a fibrin sealant patch. There were insufficient data on the adverse effects and costs of the different interventions. At present there is moderate-quality evidence that misoprostol or vasopressin may reduce bleeding during myomectomy, and low-quality evidence that bupivacaine plus epinephrine, tranexamic acid, gelatin-thrombin matrix, ascorbic acid, dinoprostone, loop ligation, a fibrin sealant patch, a peri-cervical tourniquet or a tourniquet tied round both cervix and infundibulopelvic ligament may reduce bleeding during myomectomy. There is no evidence that oxytocin, morcellation and temporary clipping of the uterine artery reduce blood loss. Further well designed studies are required to establish the effectiveness, safety and costs of different interventions for reducing blood loss during myomectomy.

Plain-language summary: The evidence is current to June 2014. The review included 18 studies with a total of 1250 women who had myomectomy for uterine fibroids. All studies compared an intervention to reduce bleeding during myomectomy with either a placebo or no such treatment. The data available suggest that vaginal insertion of misoprostol and infiltration of vasopressin into the uterine muscle are effective in reducing bleeding during myomectomy. Limited data available also suggest that chemical dissection (such as with mesna), vaginal insertion of dinoprostone, a gelatin-thrombin matrix, tranexamic acid, infusion of vitamin C (ascorbic acid) during surgery, infiltration of a mixture of bupivacaine and epinephrine into the uterine muscles, the use of fibrin sealant patch (a surgical patch that improves blood clotting) or a tourniquet around the cervix or around both the cervix and the infundibulopelvic ligamentmay be effective in reducing bleeding during myomectomy. We found limited information on the harms (adverse effects) of the different interventions. There is moderate-quality evidence that misoprostol reduces blood loss by between 70.24 ml and 125.52 ml; with a laparotomy vasopressin reduces blood loss by between 392.51 and 507.49 ml during myomectomy, and by between 121.73 ml and 172.17 ml during laparoscopic myomectomy. There is low-quality evidence for the rest of the interventions (chemical dissection, dinoprostone, gelatin-thrombin matrix, tranexamic acid, vitamin C, mixture of bupivacaine and epinephrine, a fibrin sealant patch and the two types of tourniquet).