Ultrasonographic assessment of kidney dimensions in first six months of life.

The kidney growth in children is not linear. The aim of this study was to define normal dimensions of kidneys in healthy infants during the first six months of life. A prospective ultrasonographic screening of 1870 kidneys in 935 healthy full-termed infants (476 males, 459 females) was done throughout a 5-year period. Measured kidneys were divided into six age groups according to gender and side. In the first three months of life males had both kidneys longer than same-age females (p < 0.05). In the next three-month-period the difference between sexes was not significant (p > 0.05). Left kidneys were longer than right kidneys in both sexes in the first six months of life (p < 0.01). Four nomograms with normal values of kidney lengths, according to age, sex and side were done in newborns and infants in the first 6-months of life.