A Cochrane review included 2 studies with a total of 550 subjects. Vacuum aspiration was associated with statistically significantly decreased blood loss (-17ml WMD, 95% CI -24 to -10ml), less pain (RR 0.74, 95 CI 0.61 to 0.90) and shorter duration of procedure (-1.2 minutes WMD, 95% CI -1.5 to -0.87 minutes) than sharp curettage, in the single study that evaluated these outcomes.