Epidemiological surveillance of congenital heart defects: the Tetralogy of Fallot in the Valencian Region, 2007-2017

Background: Tetralogy of Fallot is characterized by the presence of four congenital heart defects. Objective: to describe the temporal trend and distribution of Tetralogy of Fallot. in children under one year in the Valencian Region. Methods: Cases with Tetralogy of Fallot (code Q21.3 from the ICD10-British Paediatric Association) were selected from the Congenital Anomalies Population-based Registry between 2007-2017. Prevalence per 10,000 births with 95%CI was calculated, and a descriptive analysis of sociodemographic and clinical variables was made. Results: 165 cases were identified (43.6% male. 30.9% female and 25.5% unknown). The overall prevalence was 3.1/10,000 births (95%CI:2.6 3.6), being 2015 and 2017 the years with the highest (4.3/10.000 births and 4.7/10,000 births respectively) and 2011 with the lowest (1.8/10,000 births). 72.1% were live births, 24.8% Termination of Pregnancy for Fetal Anomaly (TOPFA) and 3.0% stillbirths. The prevalence in live births was 2.2/10.000 births (95%CI:1.8-2.7) and in TOPFA it was 0.810,000 births (95%CI:0.5-1.0). identifying an increasing trend along the period in the last one. 10.1% of live births died during the first year of life and 55.8% were diagnosed prenatally. Mothers younger than 20 years had the highest prevalence (4.8/10,000 births). Conclusions: The prevalence obtained in the Valencian Region was slightly lower than EUROCAT's but coincides with that of the registries that are closer geographically, and in all of them it is noted that their increasing trend specifically affects cases ending in TOPFA.