Congenital Hypothyroidism and Kidney and Upper Urinary Tract Anomalies in Neonates; Is There Any Association?

Background: In the last twenty years, there has been a noticeable rise in the occurrence of extra-thyroidal congenital anomalies in people diagnosed with Congenital Hypothyroidism (CH). This study seeks to investigate the frequency of additional Kidney/Urinary Tract Anomalies (KUTAs) in a group of children with confirmed Permanent Congenital Hypothyroidism (PCH).Methods: This retrospective study was conducted in Isfahan, Iran, utilizing data from the newborn screening database, where TSH test results from the Guthrie heel pinprick test were accessible. Patients diagnosed with PCH were included in the study. We excluded patients who died before three years and those who migrated to other provinces. All participants underwent ultrasonography and additional diagnostic measures, if necessary, to assess the presence of KUTAs.Results: The study included 1091 patients with CH, of whom 74 (6.78%) also had additional KUTAs. Specific anomalies included hypospadias (1.5%), undescended testes (UDT) (1.2%), renal agenesis (0.6%), pyelocaliceal system anomalies (1.6%), hydrocele/varicocele (0.7%), and vesicoureteral reflux (0.1%). Regression analysis showed a higher likelihood of KUTAs in cases of Cesarean Section (C/S) delivery and a history of first-degree consanguineous marriage (OR=2.27, 95% CI (0.4-13.04); OR=3.34, 95% CI (0.43, 26.07), respectively). However, these observed associations were not statistically significant (P-value 0.05).Conclusion: Our findings highlight a significant link between PCH and the occurrence of KUTAs. Therefore, a thorough kidney assessment is necessary for all confirmed PCH patients.