Diagnostic Accuracy of Antenatal Ultrasound in Diagnosis of Multicystic Dysplastic Kidneys

Objective: To establish the diagnostic accuracy of prenatal detection of unilateral and bilateral MCDK at our tertiary foetal medicine center and identify the association of MCDK with other renal or extra-renal abnormalities.

Methods: This was a retrospective observational study of all the MCDK cases diagnosed either antenatally or postnatally between January 2009 and December 2018 in our tertiary center.

Results: We identified 70 cases that were suspected or diagnosed with MCDK in the 10 year period. 11 cases were suspected to have bilateral disease antenatally opted for termination of pregnancy. However these could not be confirmed as post-mortem data was not available. 2 cases had miscarriages due to associated co-morbidities.

Correct antenatal diagnosis was made in 43 cases, 7 cases were false positive as alternative postnatal diagnosis was made and remaining 7 cases were found to have normal scans. Amongst false positive cases hydronephrosis was found in 3, Cortical Cysts in 2 cases and no abnormality in 2 cases postnatally. Associated renal or extra renal abnormalities were found in 13 patients.

Conclusions: The diagnostic accuracy of antenatal ultrasound in our center was 86% with a positive predictive value of 0.8. Associated anomalies were found in 19% of patients. This is comparable to published figures and can be used to guide antenatal counselling accurately.