Signe Altmäe1,2, Ganesh Acharya3, Andres Salumets1,4,5. 1. Competence Centre on Health Technologies, Tartu, Estonia. 2. Department of Biochemistry and Molecular Biology, Faculty of Sciences, University of Granada, Granada, Spain. 3. Department of Clinical Science, Intervention and Technology, Karolinska Institute and Centre for Fetal Medicine, Karolinska University Hospital, Stockholm, Sweden. 4. Department of Obstetrics and Gynecology, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia. 5. Department of Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.