Tocolytics in Reduction of Incidence of Spontaneous Preterm Births

Background and Aim : Globally, about 15 million pregnancies each year end in preterm birth, before the37th week of gestation, which is a major cause of morbidity and mortality in children. Various interventionshave been attempted to reduce the risk of preterm birth in women at increased risk, including tocolytic,progesterone, cervical cerclage, and cervical pessary.Methods : We searched Medline, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials,and ISI Web of Science up to 2019 and screened the outcome s abstract of systematic reviews and includedstudies of tocolytic, Beta-agonists, calcium channel blockers, oxytocin receptor antagonists, prostaglandinsynthetase inhibitors.Results : The evidence to support the use of magnesium sulfate or nitric oxide donors as a tocolytic is poor.Compared to placebo or no treatment, there is evidence to support the efficacy of calcium channel blockers(mainly nifedipine), prostaglandin synthetase inhibitors (mainly indomethacin and sulindac), oxytocinreceptor antagonists (mainly atosiban) and 2-agonists (mainly ritodrine, terbutaline, salbutamol andfenoterol). Maternal safety concerns have reduced the use of 2-agonists. Fetal safety and gestational agerestrictions have largely condemned prostaglandin synthetase inhibitors to second-line therapy. First-linetherapy in Europe and other parts of the world outside the USA and Australia is limited to calcium channelblockers and oxytocin receptor antagonists. With respect to efficacy, atosiban and nifedipine are similar,but the robustness of the evidence favours atosiban. With respect to safety, atosiban is clearly the safesttocolytic as there are fetomaternal concerns with nifedipine, particularly in high daily doses.Conclusion : Efforts continue to develop and introduce other or better agents, including novel compoundssuch as progesterone, PGF2α antagonists and statins.

کلیدواژه ها:

Beta-agonists ، calcium channel blockers ، oxytocin receptor antagonists ، tocolytics ، pretermlabour