[1] Univ Ljubljana, Fac Med, Vrazov Trg 2, Ljubljana 1000, Slovenia
[2] Univ Zagreb, Sch Med, Salata Ul 2, Zagreb 10000, Croatia
[3] Rho Sigma Res & Stat, Topniska Ul 45, Ljubljana 1000, Slovenia
[4] Sch Publich Hlth Andrija Stamparja, Sch Med, Salata Ul 2, Zagreb 10000, Croatia
[5] Univ Med Ctr Ljubljana, Div Obstet & Gynecol, Neonatal Intens Care Unit, Dept Perinatol, Slajmerjeva Ul 3, Ljubljana 1000, Slovenia
[6] Dept Pediat Surg & Intens Therapy, Div Surg Serv, Pediat Intens Care Unit, Bohoriceva Ul 20, Ljubljana 1000, Slovenia
[7] Univ Ljubljana, Fac Med, Dept Pediat, Vrazov Trg 2, Ljubljana 1000, Slovenia