Blunt versus sharp uterine incision expansion during low transverse cesarean delivery: a metaanalysis

We sought to review and update available evidence regarding outcomes after cesarean delivery (CD) using blunt vs sharp expansion of the uterine incision.

We queried the database of PubMed (US National Library of Medicine, 1946 through December 2013), the Cochrane Library Database of Systematic Reviews, ClinicalTrials.gov, and Web of Science. All relevant bibliographies were reviewed. Randomized controlled trials comparing blunt with sharp expansion of the lower segment during CD were evaluated for inclusion and methodological quality. The primary outcome was occurrence of unintended extensions. Secondary outcomes were drop in hematocrit or hemoglobin and estimated maternal blood loss, need for transfusion, operative time, use of uterotonics, rate of endometritis, and neonatal outcomes. Data extraction, analysis, and results were based on the preferred reporting items for systematic review and metaanalysis guidelines.

Six randomized controlled trials (2908 patients) were included. Blunt expansion technique was associated with lower drop in postoperative hematocrit (weighted mean difference [WMD], -1.07%; P = .05) and hemoglobin (WMD, -0.64 g/dL; P < .05), lower rate of unintended extensions (pooled relative risk, 0.47; P < .05), and a shorter operative time (WMD, -2 minutes; P < .05). Lower estimated blood loss was also observed but the difference was not significant (WMD, -88.07 mL; P > .05). There were no differences in the rates of blood transfusion, endometritis, use of uterotonics, and neonatal outcomes between both techniques.

Blunt expansion of uterine incision during CD is associated with less unintended extensions and favorable maternal outcomes. Although the drop in hemoglobin, hematocrit, and operative times were in favor of blunt expansion, the degree of reduction may not be clinically relevant.