The study aims to assess the incidence and the risk factors of nephrocalcinosis in very preterm infants using patient data collected during hospitalisation at the Neonatology Centre.

Nephrocalcinosis in preterm infants develops as a result of imbalance between the factors promoting or inhibiting formation of kidney stones. It is caused by intensive treatment as well as functional and morphological kidney immaturity. There is a correlation between the prevalence of nephrocalcinosis and low gestational age.

The study aims prospectively to assess the incidence and the risk factors of nephrocalcinosis in very preterm infants less than 32 weeks of gestation.

Inclusion Criteria:

• preterm infants of the gestational age of <32 weeks;
• parental consent acquired.

Exclusion Criteria:

• death before 28 days of age;
• congenital defects;
• no kidney ultrasound results;
• no parental consent.

The study population is a group of very preterm infants less than 32 weeks of gestation during hospitalisation at the Neonatology Centre.