Down Syndrome in Brazil: Occurrence and Associated Factors

Area of Science:

• Genetics
• Public Health
• Epidemiology

Background:

• Down syndrome is the leading genetic cause of intellectual disability.
• Accurate incidence data in Brazil was previously unclear.
• This study addresses the need for Brazilian Down syndrome occurrence statistics.

Purpose of the Study:

• To estimate Down syndrome incidence in Brazil from 2012-2018.
• To analyze associations with maternal, paternal, and gestational factors.
• To examine links with newborn vitality indicators.

Main Methods:

• Retrospective analysis of Brazilian birth certificates (2012-2018).
• Statistical analysis using Pearson's chi-square and logistic regression.
• Utilized Stata 14.1 software with a 95% CI and 5% significance level.

Main Results:

• 157 Down syndrome cases identified among 386,571 live births.
• Incidence rate found to be 4 per 10,000 live births.
• Significant associations noted with maternal age ≥35, paternal age ≥30, ≥6 prenatal visits, prematurity, and low birth weight.

Conclusions:

• Maternal age of 35 and above increases the likelihood of Down syndrome.
• Premature birth, low birth weight, and adequate prenatal care (≥6 visits) are associated with Down syndrome.
• Findings provide crucial epidemiological data for Down syndrome in Brazil.