title: Double blind trial of ritodrine and placebo in twin pregnancy.
mesh_terms: D000318:Adrenergic beta-Agonists / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000517:prevention & control*; D011247:Pregnancy; D011272:Pregnancy, Multiple; D014427:Twins
chemical_list: D000318:Adrenergic beta-Agonists