ObjectiveTo systematically review the efficacy and safety of intravenous calcium infusion for preventing ovarian hyperstimulation syndrome (OHSS). MethodsDatabases including PubMed, EMbase, The Cochrane Library (Issue 7, 2015), CNKI, Sinomed and WanFang Data were searched from inception to July 2015 to collect randomized controlled trials (RCTs) and non-RCTs about intravenous calcium infusion for OHSS. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed using RevMan 5.3 software. ResultsA total of six studies involving 1 061 women were included. The results of meta-analysis showed that intravenous calcium infusion could reduce the incidence of moderate OHSS (RR=0.27, 95% CI 0.11 to 0.65, P=0.003), but not the incidence of severe OHSS (RR=0.77, 95% CI 0.23 to 2.63, P=0.68). In addition, intravenous calcium infusion had a tendency to increase the pregnant rate (RR=1.19, 95% CI 0.94 to 1.50, P=0.15). The subgroup analysis showed that, compared with placebo/no treatment, intravenous calcium infusion reduced the incidence of moderate OHSS, but not the incidence of severe OHSS. There were no statistical differences between intravenous calcium infusion and other positive control (cabergoline and hydroxyethyl starch) in the incidence of OHSS and pregnant rate. No side effect was reported in the studies included. ConclusionsCurrent evidence indicates that intravenous calcium infusion can reduce the incidence of OHSS without influence pregnant outcomes. Due to the quantity and quality limitations of included studies, more high quality case-control or cohort studies are needed to verify the above conclusions.