Prenatal diagnosis of urinary tract anomalies, a cohort study in the Northern Netherlands

OBJECTIVE: To describe prevalence, time of diagnosis and type of birth in children and fetuses with urinary tract (UT) anomalies after the introduction of the anomaly scan in the Netherlands in 2007. METHODS: We selected, from a population-based congenital anomaly registry, children and fetuses with UT anomalies born between 2008-2014. Cases were defined according to type of UT anomaly and whether isolated or with associated anomalies. Information was collected on time of diagnosis and type of birth. RESULTS: We included 487 cases. Total prevalence increased from 34.0 in 2008 to 42.3 per 10,000 births in 2014, mainly by an increase in anomalies of the collecting system. Almost 70% presented as isolated. Anomalies of the renal parenchyma were more often associated with genetic or other anomalies (47.3%) than anomalies of the collecting system (19.0%). The proportion of prenatally diagnosed cases increased from 59.3 % in 2008 to 80.9% in 2014. Termination of pregnancy occurred in 14.8%, of which the majority were UT anomalies associated with a genetic disorder or other anomalies. CONCLUSION: In the period after the introduction of the anomaly scan we observed an increasing prevalence of anomalies of the collecting system, but no increase in termination of pregnancies