NCT04459117.

Study name	Prophylactic treatment of the ductus arteriosus in preterm infants by acetaminophen (TREOCAPA)
Methods	Phase II/III European multicentre randomized controlled trial
Participants	Inclusion criteria Birth between 23 to 26 weeks for Phase II, between 23 to 28 weeks for Phase III Post natal age < 12 hours Parental or Legal Authority Consent Parents with a social security or health insurance (if applicable according to the local regulation) Exclusion criteria Birth defect /congenital anomaly Twin‐to‐twin transfusion syndrome Suspicion of pulmonary hypoplasia Suspicion of hepatic impairment (haemorrhagic syndrome and/or severe hypoglycaemia) Clinical instability that can lead to rapid death Impossibility to start treatment before 12 hours of life Parents placed under judicial protection Participation in other clinical trial using acetaminophen during the first 5 days of life, indomethacin or ibuprofen during the first 3 days of life or using rescue treatment of PDA not recommended in the TREOCAPA trial
Interventions	Intervention arm: acetaminophen In the 27 to 28 weeks gestational age group, the dosage is 2 mL/kg loading dose within 12 hours after birth followed by 0.75 mL/kg/ 6 hours during 5 days (total = 20 doses). In the 23 to 26 weeks gestational age group, the dosage will be minimum effective dose of acetaminophen to close the ductus arteriosus before or at day 7, found during the phase II. Contol arm: placebo (0.9% NaCl)
Outcomes	Primary outcome measure: closure of ductus arteriosus
Starting date	29 October, 2020
Contact information	Jean‐Christophe Rozé, Institut National de la Santé Et de la Recherche Médicale, France(jean-christophe.roze@inserm.fr)
Notes	Estimated enrolment: 824 infants Estimated primary completion date: April 2023

NaCl: sodium chloride.