PHYSICAL AND NEUROPSYCHIC DEVELOPMENT IN INFANTS DEPENDING ON THE VITAMIN D LEVEL IN THE UMBILICAL CORD BLOOD
In order to investigate the role of prenatal sufficiency of 25-hydroxyvitamin D3 (25(OH)D3) in the postnatal development of infants, a dynamic assessment of physical (PD) and neuropsychic development (NPD) was carried out in comparison with the level of 25(OH)D3 in umbilical cord blood in newborns, upon reaching 40 weeks of post-conceptual age (PCA); at 3, 6 and 12 months of corrected age (CA). Materials and Methods: A prospective observational study of 118 children born between 24 and 41 weeks of gestational age was carried out, of which 52 were premature (group 1) and 66 were term infants (group 2). Evaluation of 25(OH)D3 level in cord blood serum was carried out. using an immunochemical analyzer UniCel DxI600 Beckmancoulter, USA. To assess PD indicators (body weight, height, head circumference), the Intergrowth-21st nonparametric method was selected using an online postnatal growth calculator. NPD was assessed according to the CAT/CLAMS and Zhurba -Mastyukova's scales. Comparing the developmental age with the actual age, the developmental coefficient was calculated as a percentage, the value of which >75 % indicated that the NPD corresponded to the actual or corrected age of the child. Research results and discussion: The median of the 25(OH)D3 indicator in the 1st group was 17,63 ng/l, 95 % CI / Q1-Q3: 10,07-21,39; in group 2 - 23,76 ng/l, 95 % CI / Q1-Q3: 17,2-39,34 (p < 0,001). Severe deficiency of 25(OH)D3 (below 10 ng/ml) was observed more often in premature infants (25 %) and only in 9,1% of term infants (p = 0,03). A direct statistical dependence of the growth rates in both full-term and premature infants in compare of 25(OH)D3 in cord blood after they reach 12 months of CA (p = 0,049, p = 0,036, respectively) was proved. In the group of premature infants a statistically significant relationship between speech developmental disorders (coefficient of speech development CAT/CLAMS <75 %) and low 25(OH)D3 status in umbilical cord blood was found (p = 0,034). The threshold value of 25(OH)D3 in umbilical cord blood at the cut-off point, which corresponded to the highest value of the Youden index, was 15,33 ng/ml. When the value of 25(OH)D3 in the umbilical cord blood was higher or equal to this value, the gradation of the speech development coefficient was predicted to be >75 % in compare of the age norm. The sensitivity and specificity of the method were 75,3 and 55 %, respectively. Conclusions: In order to produce preventive measures it is necessary to continue further study of low vitamin D prenatal supply influence on PD and NPD in the near and long-term prognosis in children.