OBJECTIVE: Foetal growth retardation (FGR) is a leading cause of perinatal death and long-term harms at survivors. Placental infarction plays a role in FGR, yet, no trials have evaluated whether low molecular weight heparins increase birth weight in ongoing FGR pregnancies.METHODS: An open-labelled randomized trial in Denmark during 2011-2016, including singleton pregnant women with FGR (estimated foetal weight