<prompt> The neonatal kidney achieves concentrating ability equivalent to adults kidney byOne year of ageEighteen months of ageThree to six months of ageJust before puberty  <response>: Normal adult kidney can produce urine with an osmolality of greater than 1000 m Osmkg water The healthy newborn infant, subject to water deprivation for 10-14 hours can achieve an osmolality of only 500-700 m Osm kg. This value increases gradually during the first few months and approximates to the adult value by about one year of age.On the other hand, the newborn can dilute his urine to a minimum of 50 m Osmkg much like an older child. 