Background: The growth rate is an important indicator of the child's health state. Premature newborns require an especially exact and reliable assessment of their growth which should include, above all, their maturity.
Aim: The evaluation of the influence of newborn's maturity on its growth rate during 2 first years of life.
Material and methods: Prospective, longitudinal cohort study. 159 newborns born < or = 32 weeks of gestation discharged from 3rd level NICU were divided into 2 cohorts: A) born between 24-28 weeks (n = 83) and B) born between 29-32 weeks (n = 76). Before discharge and then every month in the 1st year of life and every 3 months in the 2nd year of life weight, length, head circumference and chest circumference were measured.
Results: Median length in 6th month was 622 mm in group A and 650 mm in group B (p < 0.05), after 1 year 720 mm vs 745 mm (p < 0.05), and after 2 years 819 mm vs 853 mm (p < 0.05). Median weight was 6010 vs 7160 g (p < 0.05), 8210 vs 9410 g and 9965 vs 11,260 g (p < 0.05), median chest circumference 40 vs 42 cm (p < 0.05), 44 vs 46 cm (p < 0.05) and 46 vs 47.5 cm (p < 0.05) and median head circumference 42 vs 43 cm (p < 0.05), 45 vs 46 cm (p < 0.05) i 47 vs 48 cm (p = 0.06). The results were also presented as growth charts.
Conclusions: The newborns born between 29-32 week of gestation have faster growth rate than newborns born between 24-28 week of gestation. The assessment of development of extremely premature newborns should be based on growth charts prepared separately for a given gestational age.