1. Institute for Child and Youth Health Care of Vojvodina, Novi Sad, Serbia
2. Faculty of Medicine, University of Novi Sad, Serbia
3. Institute for Mother and Child “dr Vojkan Cupic” Belgrade, Serbia
4. Faculty of Medicine, University of Belgrade, Serbia
5. Outpatient Clinic Ob & Gyn Rogaška Slatina, Slovenia
6. Faculty of Medicine, University of Maribor, Slovenia