University of Tartu is an academic institution with main focus on under- and postgraduate teaching and research. Tartu University Clinics is a multidisciplinary hospital with 986 beds covering the population of 500,000 and 5,000 annual births. The other institution involved is Tallinn Children’s hospital that for neonatal cases covers an area with the population of 800,000 with 10,000 births per year. Both hospitals are tertiary care referral centres with about 700 babies treated (about 60% mechanically ventilated) in the third level NICU annually. At the Institute of Medical Microbiology we have formed a research group for clinical studies. The group consist of neonatologists, pharmacologists, microbiologists and statisticians. The group is actively involved in clinical studies mainly in critically ill patients.