Four years follow-up of 101 children with melamine-related urinary stones

The melamine-contaminated milk powder incidence occurred in China in 2008. Many studies have been published regarding the epidemiology, clinical symptoms, diagnosis and treatment of melamine-related urinary stones. The objective of this study is to follow-up the effects of melamine-contaminated milk powder consumption on kidney and body growth in children with melamine-related urinary stones 4 years ago. One hundred and one children with melamine-related urinary stones were followed up by urinalysis, renal function tests and urinary ultrasonography. The data of body weight and height, clinical signs and complications were collected. Eighty normal children without the history of consuming melamine-contaminated milk powder were collected as controls. Eighty-one children with melamine-related urinary stones were successfully followed up. Of 45 cases with melamine-related urinary stones treated conservatively after discharge, 34 disappeared completely, 6 dissolved partially, 1 increased in size and 4 did not change at 4 years follow-up. The percentages of under-height and under-weight infants were significantly higher in melamine-related urinary stones group compared to the controls, respectively (p < 0.05). Routine blood, renal and bladder function tests as well as urinalysis were normal in all children. No urological tumors were detected. No noticeable impact of melamine-related urinary stones on kidney and bladder was found at 4 years follow-up. However, whether or not melamine-related urinary stones had effect on body growth needs follow-up in future.