Abstract
Congenital anomalies (CA) can be detected prenatally through imaging and specialized procedures. On December 30, 2020, Argentina passed the Termination of pregnancy (TOP) law. This study assesses the impact of this legislation on the epidemiological profile of CA, in relation to access to prenatal diagnosis and the practice of legal termination of pregnancy due to fetal anomalies. A before-and-after study design was used, comparing two three-year periods: 2015–2017 and 2021–2023, using data from the National Network of Congenital Anomalies of Argentina (RENAC). A survey was also conducted among obstetric and prenatal diagnosis professionals from 70 maternity hospitals. In the second period, a significant decrease was observed in the prevalence of anencephaly, hydrocephalus, Down syndrome, and disruptive anomalies. The percentage of hospitals performing prenatal procedures (nuchal translucency measurement, first trimester screening, detailed ultrasound, and karyotyping) increased. While 51% of the institutions reported performing legal terminations in the first trimester for fetal anomalies in the first period, this rose to 87.1% in the second. The decline in major nervous system anomalies is likely associated with greater access to prenatal screening and legal terminations. The decrease in Down syndrome prevalence, despite rising maternal age, may reflect improved prenatal detection and access to TOP. The reduction in disruptive anomalies may be related to a decrease in unsafe, clandestine abortions following the legalization of TOP.