Chawanpaiboon S.Pooliam J.Mahidol University2026-03-162026-03-162026-01-01International Journal of Women S Health Vol.18 (2026)https://repository.li.mahidol.ac.th/handle/123456789/115747Aim: Management of threatened preterm labour (TPL) frequently involves tocolytic drug administration, which may lead to unnecessary interventions and maternal complications, especially in women at low risk of imminent preterm birth. Cervical length measurement is a reliable method for assessing preterm birth risk and guiding appropriate management. However, tocolytic drugs and antenatal corticosteroids are often overused in women with adequate cervical length. Methods: This randomised controlled trial compared the effectiveness of bed rest versus tocolytic therapy in women with threatened preterm labour and a cervical length ≥ 20 mm. Participants were allocated to either bed rest or tocolytic treatment. Primary outcomes included preterm delivery rates and birth weight. Secondary outcomes were caesarean section rates, antenatal corticosteroid use, maternal complications, and healthcare costs. Results: Women receiving tocolytic therapy had a significantly higher rate of antenatal corticosteroid use (79%, p < 0.0001) and increased caesarean section rates compared with those managed with bed rest. Birth weight was higher among the bed rest group. No differences were found in preterm delivery rates or maternal complications between groups. Conclusion: Bed rest alone is sufficient for managing threatened preterm labour in women with a cervical length ≥ 20 mm. The use of tocolytic drugs in this low-risk population may result in unnecessary interventions, higher caesarean rates, and increased healthcare costs. Bed rest is a safe, effective, and cost-efficient alternative to pharmacologic therapy in preventing preterm delivery while minimising maternal complications. Trial Registration Page: https://www.thaiclinicaltrials.org/show/TCTR20200617001: 17/06/2020.NursingMedicineArticleSCOPUS10.2147/IJWH.S5765802-s2.0-10503241513511791411