ObjectiveTo systematically review the effectiveness and safety of atosiban in the treatment of threatened premature labor. MethodsWe electronically searched databases including The Cochrane Library, EMbase, PubMed, CBM, CNKI, WanFang Data and VIP for randomized controlled trials (RCTs) on atosiban for threatened premature labor from inception to October 2012. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data, and assessed the methodological quality of included studies. Then, meta-analysis was performed using RevMan 5.2 software. ResultsA total of 11 RCTs involving 2 542 cases of threatened preterm labor were included. The results of meta-analyses showed that atosiban was superior to β2 adrenergic receptor agonists in effectiveness (48 h:OR=1.33, 95%CI 1.06 to 1.66, P=0.01; 7 d:OR=1.36, 95%CI 1.12 to 1.65, P=0.002) and maternal tolerability (48 h:OR=1.65, 95%CI 1.34 to 2.06, P < 0.01; 7 d:OR=1.65, 95%CI 1.34 to 2.02, P < 0.01), but its effectiveness was similar to calcium antagonists (48 h:OR=0.94, 95%CI 0.55 to 1.60, P=0.82; 7 d:OR=0.92, 95%CI 0.53 to 1.60, P=0.77). There were no significant differences in gestational age (MD=0.20, 95%CI-0.16 to 0.56, P=0.27), the incidence of cardiovascular adverse effects in the mother's body (OR=0.07, 95%CI 0.01 to 1.05, P=0.05), birth weight (MD=-13.20, 95%CI-77.84 to 51.44, P=0.69), and the incidences of asphyxia (OR=2.08, 95%CI 0.89 to 4.87, P=0.09), sepsis (OR=0.78, 95%CI 0.54 to 1.14, P=0.20) and respiratory distress syndrome (OR=1.03, 95%CI 0.65 to 1.65, P=0.89) between the atosiban and β2 adrenergic receptor agonist groups. But its incidence of cardiovascular adverse effects in the mother's body was significantly lower than calcium antagonists (OR=0.001 4, 95%CI 0.02 to 0.82, P=0.05). ConclusionAtosiban is better than other tocolytics in controlling the uterine contraction, and it could significantly prolong gestational age, with less maternal side effects and more tolerability. It is safer than other tocolytics in the treatment of threatened premature labor. It could be used as a first-line drug for the treatment of acute preterm contractions because of its high specificity in the uterus.