Abstract
Forty four fetuses with multicystic dysplastic kidney (MCDK) disease recognised on antenatal ultrasound were studied prospectively. In nine aborted fetuses and in five who died in the neonatal period the MCDK disease was bilateral or there were associated lethal abnormalities or syndromes. All surviving infants had unilateral disease and in six (20%) there was significant reflux into the normal contralateral kidney. Since 1988 the management of unilateral MCDK disease has been conservative with no child developing sepsis, hypertension, or malignancy. Serial ultrasound examinations suggest that MCDK lesions involute with time and conservative rather than operative management is favoured.