Objective: We developed a research usefulness tool collating published criteria and examined if randomised controlled trials (RCTs) addressing preterm birth were useful. Search Strategy: Cochrane library. Selection Criteria: Published RCTs within 56 preterm birth Cochrane reviews. Data Collection and Analysis: A usefulness tool was developed with eight criteria combining 13 items identified through literature searches and consensus. RCTs were evaluated for compliance with each item by multiple assessors (reviewer agreement 95-98%). Proportions with 95% confidence interval (CI) were calculated and compared for change over time using ≧ 2010 as a cut-off, with relative risks (RR). Main Results: Among 350 selected RCTs, only 38 (11%, 95% CI 8-15%) met half of the usefulness criteria. Compared to trials before 2010, recent trials used composite or surrogate (less informative) outcomes more often (13% vs 25%, RR 1.87, 95% CI 1.19-2.93). Only 17 trials reflected real life (pragmatism) in design (5%, 95% CI 3-8%), with no improvements over time. No trials reported involvement of mothers to reflect patients’ top priorities in question definition or outcomes selection. Recent trials were more transparent with prospective registration (0.5% vs 28%, RR 58, 95% CI 8-420%), availability of protocol (0.5% vs 15%, RR 32, 95% CI 4-237%) and data sharing statements (2% vs 8%, RR 3, 95% CI 1-10%). Conclusion: Clinical trials in preterm birth lacked many usefulness features, with one tenth of trials meeting half of the items evaluated. Use of informative outcomes, patient centeredness, pragmatism and transparency should be key targets for future research planning.