Analysis of the incidence of trisomy of chromosome 21 in pregnancies across different age groups between 2000 and 2020

Objective: This study investigated the relationship between maternal age and the risk of trisomy 21 (T21) in mothers over 35 years old by analyzing the incidence of T21 in Brazil from 2000 to 2020. Methods: A descriptive quantitative and cross-sectional methodology was employed, with data collected from the DATASUS database and the Integrated Health Surveillance Platform. IBM SPSS Statistics v23 software was used for statistical analysis. Results: A decrease in pregnancies among younger mothers (15-24 years) and stable numbers for mothers over 35 were observed. There was a significant increase in births of children with T21 from mothers over 35 in the last decade. Conclusion: Data suggest the influence of biopsychosocial factors on the significant increase in births of children with T21 from mothers over 35, as the total number of pregnancies in this age group did not vary significantly over the two decades analyzed.