[1] Trondheim Reg & Univ Hosp, St Olavs Hosp, Dept Clin Serv, PB 3250 Sluppen, N-7006 Trondheim, Norway
[2] Norwegian Univ Sci & Technol, Fac Med & Hlth Sci, Dept Lab Med, Childrens & Womens Hlth, Trondheim, Norway
[3] Norwegian Univ Sci & Technol, Fac Med & Hlth Sci, Dept Publ Hlth & Nursing, Trondheim, Norway
[4] Trondheim Municipal, Dept Physiotherapy, Trondheim, Norway
[5] Modena Univ Hosp, Inst Pediat & Neonatal Med, Modena, Italy
[6] Modena Univ Hosp, NICU, Modena, Italy