Multicystic kidney dysplasia: a prospective study on the natural history of the affected and the contralateral kidney

Abstract

In a 6-year period, 41 young infants with multicystic kidney dysplasia were seen in our department. In 30 cases, the diagnosis had already been suspected by prenatal ultrasonography. A prospective protocol was proposed to the parents which comprised ultrasound evaluation every 3 months until the age of 24 months and renal function assessment at the age of 18 months. In 33 patients, the study was completed as scheduled. At the start of the study, the maximal diameter of the multicystic kidney was above the mean length of normal kidneys in all cases where precise measurement was possible. Within 24 months, 7 of the dysplastic kidneys disappeared, 20 regressed in size, 1 remained unchanged and only 5 increased in size. Between the age of 0 to 3 months, renal length of the contralateral kidney was within the normal range in 19 infants and above +2SD in 14 cases. At the age of 18 to 24 months, renal length was, with few exceptions, between 0 and +4SD. Inulin clearance was normal in all 33 individuals with a median value of 112 ml/min per 1.73 m².

Conclusion As a rule, multicystic kidneys shrink in the first 2 years of life. In most cases the contralateral kidney maintains a normal renal function as a consequence of progressive compensatory hypertrophy.