Posterior urethral valves and the risk of neurodevelopmental disorders in two FINNISH cohorts

Abstract

The Posterior Urethral Valve (PUV) is a persistent membrane of the urethra, which causes obstruction in the urogenital tract in boys. To our knowledge, no comprehensive reports have been published on whether PUV is associated to neurodevelopmental disorders. Here, we analyzed a cohort of PUV patients for neurodevelopmental disorders and verified findings in an older cohort. In a register based study, we reviewed the hospital registries for patients treated for PUV during 1992-2013 to identify those with neurodevelopmental disorders. Primary outcome measure was any neurodevelopmental diagnosis. Secondary outcome measures were specific disorders: ASD; ADHD, intellectual disability, learning disabilities. Birth weight and gestational age were recorded, serum creatinine levels at specific timepoints were noted. We then investigated these variables to see any correlations to neurodevelopmental disorders. We replicated the strategy for verification in an older cohort of PUV-patients, who had been treated in our institute during 1970-1991. We identified 87 patients treated for PUV of which thirteen (15%) had a verified diagnosis of a neurodevelopmental disorder. 2.3% of PUV patients fulfilled criteria of mild intellectual disability (F70.0/F79.0), 9% had ADHD/ADD-spectrum diagnoses (F90.0/F90.9) and 2.3% had learning disabilities (F83/F81.3). 5.7% of patients presented with difficulties in social interactions (F93.89, F94.8). Five patients presented with more than one neurodevelopmental diagnosis. We confirmed these findings in the older cohort of patients, where a verified neurodevelopmental diagnosis was detected in 14% of patients. We identified no statistically significant associations to gestational age, birth weight or creatinine levels of PUV-patients with neurodevelopmental diagnoses as compared to the PUV-patients not diagnosed for neurodevelopmental disorders. Intellectual disability/mental retardation was more prevalent in our material and this association was statistically significant. We show, that the prevalence of intellectual disability among PUV patients exceeds the cumulative prevalence in Finland in both cohorts analyzed here. 15% of PUV-patients presented with a diagnosis of a neurodevelopmental disorder. To our knowledge, this is the first study attempting to outlineneurodevelopmental disorders among boys with PUV. This study has limitations. It is register based and only diagnoses made at an institute within our hospital district are considered. The PUV-patients may be under closer surveillance than age-matched healthy children, which may lead to an overrepresentation of cases. The patient number is small and the small subsets of patients within each cohort hamper any further statistical analysis. The neurodevelopmental impacts of pediatric general anesthesia remain elusive and may have corollaries which must be kept in mind when interpretating our results. Patients with PUV require close follow-up in a multi-disciplinary manner, not forgetting neurodevelopmental aspects. Attention to intellectual disability is mandatory. Any suspicion of a developmental delay in a patient with PUV warrants further investigation and corresponding interventions.