Prevalence of congenital anomalies in newborns: a cross-sectional study in the state of Rio de Janeiro, Brazil, 2019-2021.

Objective: To describe prevalence of congenital anomalies according to maternal, health care, and newborn characteristics in the state of Rio de Janeiro, from 2019 to 2021.

Methods: This was a cross-sectional study. Live births were described according to sex, birthweight, gestational age, Apgar score, and maternal sociodemographic, reproductive, and health care characteristics. Data were obtained from the Live Birth Information System (Sistema de Informações sobre Nascidos Vivos - Sinasc). Anomalies were classified according to the list of priority congenital anomalies for surveillance within the scope of Sinasc. We calculated prevalence rates and respective 95% confidence intervals (95%CI).

Results: The prevalence rate of congenital anomalies was 68.7/10,000 live births, and was high in children of mothers who were Black (75.9/10,000 live births), <20 years old (74.8 10,000 live births) and ≥35 years old (83.8 10,000 live births), as well as in newborns <1500 g (189.2 10,000 live births) and newborns with gestational age of 22 to 31 weeks (154.8 10,000 live births). The prevalence rate of priority anomalies was 45.8 10,000 live births, twice the prevalence of unclassified anomalies (22.9 10,000 live births). Limb defects predominated, with a prevalence rate of 22.5 10,000 live births (95%CI 21.3; 23.7), followed by heart defects, 6.5 10,000 live births (95%CI 5.9; 7.2). Oral clefts, genital organ anomalies and abdominal wall defects alternated from third to fifth positions.

Conclusions: Newborns with higher biological risk and born to women with greater sociodemographic vulnerability presented higher prevalence of anomalies. The list of priority congenital anomalies should be included in the Sinasc data tabulation programs.