FUNCTIONAL AND MORPHOLOGICAL CHARACTERISTICS OF THE KIDNEYS OF NEWBORNS WITH EXTREMELY LOW BIRTH WEIGHT
Abstract
Objective. The article discusses the problem of assessing renal function, macro and microscopic characteristics of the kidneys in premature babies born as a result of prematurely premature births with extremely low birth weight. Materials and methods. The functional state of the kidneys was evaluated in 148 children with ELBW and VLBW in the period from 1 to 90 days of postnatal age. The urine output rate, serum creatinine level, GFR calculation according to the Schwartz formula, autopsy, light microscopy and computer morphometry of kidney biopsy samples of deceased children were performed. Results. The results of the study showed that premature babies with ELBW are characterized by elevated serum creatinine levels and a low glomerular filtration rate, starting from the 4th day of life. An increase in GFR from the 3rd week of postnatal life significantly increases the likelihood of survival of premature babies with ELBW. The decrease in glomerular filtration rate in this contingent of children is associated not so much with kidney damage, but rather due to a more pronounced immaturity of nephrons. Macroscopically, the kidneys of premature babies with ELBW are characterized by a flabby consistency (65.8 %) and embryonic lobed surface (89.5 %), and the anatomical pattern of the kidney is preserved only in 57.9 %. Microscopically characteristic signs of severe immaturity of the glomeruli of the kidneys and circulatory disorders, degenerative changes in the epithelium of the tubules, necrosis of the proximal tubules - acute tubular necrosis (18.4 %). The size of the renal corpuscles and tubules exceeds the rates of full term children. Conclusion: For children with extremely low birth weight, desynchronous nephronogenesis is characteristic, characterized by an atypical increase in the size of the components of the nephron, which serves as the structural basis for reducing the functional reserve of the kidneys.
