We would like to express our gratitude to the parents for giving permission to investigate their infants and to the team of midwives, nurses, laboratory staff, and physicians involved in their care.

Collaborators

Division of Neonatology, Department of Pediatrics, Medical University of Graz, Graz, Austria: Marlies Bruckner, Corinna Binder-Heschl, Daniel Pfurtscheller, Johann Martensen, Nina Höller, Evelyn Ziehenberger, Lukas Mileder;

Comprehensive Center for Pediatrics, Department of Pediatrics and Adolescent Medicine, Division of Neonatology, Intensive Care and Neuropediatrics, Medical University of Vienna, Vienna, Austria: Katharina Goeral, Julia Buchmayer, Katrin Klebermass-Schrehof, Angelika Berger (local principal investigator), Sigrid Baumgartner, Agnes Grill, Michaela Mayr, Judith Rittenschober-Boehm, Michael Schneider;

Department of Pediatrics II, Neonatology, Medical University of Innsbruck, Innsbruck, Austria: Christina Schreiner, Vera Neubauer, Peter Wöckinger, Anna Posod;

Neonatal Intensive Care Unit, Department for Perinatology, Division of Gynaecology and Obstetrics, University Medical Centre Ljubljana, Slovenia:

Tina Perme, Lilijana Kornhauser-Cerar, Anja Marolt, Ana Dimnik, Vlasta Lubej Kurtovič;

Infant Centre, University College Cork, Cork University Maternity Hospital, Cork, Ireland:

Eugene M Dempsey, Christoph E Schwarz, Garvey Aisling, Jurate Panaviene, David Healy, Nahla Ahmed, Ita Herlihy;

Department of Neonatology, University Children’s Hospital of Tübingen, Germany:

Laila Springer, Kerstin Gründler, Axel Franz;

Neonatologia e Terapia Intensiva Neonatale (TIN) Ospedale dei Bambini “V.Buzzi,” Milano, Italia: Gianluca Lista, Ilaria Stucchi, Francesca Castoldi, Francesco Cavigioli;

II Department of Neonatology, Neonatal Biophysical Monitoring and Cardiopulmonary Therapies Research Unit, Chair of Neonatology, Poznan University of Medical Sciences, Poznan, Poland:

Tomasz Szczapa, Lukasz Karpinski.

Ginekologiczno Położniczy Szpital Kliniczny Uniwersytetu Medycznego im. Karola Marcinkowskiego w Poznańiu, Poznań, Poland: Zuzanna Kozłowska, Marcin Minta, Zuzanna Owsiańska, Sonia Kahtan, Natalia Neumann-Klimasińska, Karolina Wróbel, Agata Kubiaczyk, Katarzyna Kosik, Katarzyna Olek, Michalina Bugiera, Julita Porwolik, Agnieszka Basiukajć, Elzbieta Czapla, Wojciech Łukaszuk, Katarzyna Gryczka, Dobrochna Naskręcka, Jan Mazela, Marta Szymankiewicz-Bręborowicz;

Division of Neonatology and Pediatric Intensive Care Medicine, Center for Pediatrics and Adolescent Medicine, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany:

Hans Fuchs, Daniel Klotz, Jana Baumgartner; Institute for Maternal and.

Child Health, “IRCCS Burlo Garofolo,” Trieste, Italy:

Jenny Bua, Jana Bembich, Laura Travan;

Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada:

Georg M Schmölzer, Brenda Law, Po-Yin Cheung.'