children born at less than 37 weeks of intrauterine development and with a body weight below 2,500 g. Depending on body weight at birth, there are 4 degrees of prematurity: 1st degree – premature babies, born with a body weight of 2,001 – 2,500 g, 2nd degree – with a weight of 1,501 – 2,500 g, 3rd degree – with a weight of 1,001 – 1,500 g, 4th degree – 1,000 grams or less. Children from the 22nd week of pregnancy are considered viable.