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. 2023 Jan;43(1):40-48.
doi: 10.24095/hpcdp.43.1.04.

The Alberta Congenital Anomalies Surveillance System: a 40-year review with prevalence and trends for selected congenital anomalies, 1997-2019

[Article in English, French]
R Brian Lowry  1   2   3 , Tanya Bedard  1 , Xin Grevers  1 , Susan Crawford  4 , Steven C Greenway  3   5   6   7 , Mary E Brindle  5   8 , Harvey B Sarnat  3   9 , A Robertson Harrop  5   10   11 , Gerhard N Kiefer  11   12 , Mary Ann Thomas  1   2   3
Affiliations

The Alberta Congenital Anomalies Surveillance System: a 40-year review with prevalence and trends for selected congenital anomalies, 1997-2019

[Article in English, French]
R Brian Lowry et al. Health Promot Chronic Dis Prev Can. 2023 Jan.

Abstract
in English, French

Introduction: Current published long-term provincial or territorial congenital anomaly data are lacking for Canada. We report on prevalence (per 1000 total births) and trends in 1997-2019, in Alberta, Canada, for selected congenital anomalies. Associated risk factors are also discussed.

Methods: We used data from the Alberta Congenital Anomalies Surveillance System (ACASS) to calculate the prevalence and perform chi-square linear trend analyses.

Results: From 1997 to 2019, the overall prevalence of neural tube defects was stable, at 0.74 per 1000 total births. The same was true for spina bifida (0.38), orofacial clefts (1.99), more severe CHDs (transposition of the great arteries, 0.38; tetralogy of Fallot, 0.33; and hypoplastic left heart syndrome, 0.32); and gastroschisis (0.38). Anencephaly, cleft palate and anorectal malformation significantly decreased with a prevalence of 0.23, 0.75 and 0.54 per 1000 total births, respectively. Significantly increasing trends were reported for anotia/microtia (0.24), limb reduction anomalies (0.73), omphalocele (0.36) and Down syndrome (2.21) and for hypospadias and undescended testes (4.68 and 5.29, respectively, per 1000 male births).

Conclusion: Congenital anomalies are an important public health concern with significant social and societal costs. Surveillance data gathered by ACASS for over 40 years can be used for planning and policy decisions and the evaluation of prevention strategies. Contributing genetic and environmental factors are discussed as is the need for continued surveillance and research.

Introduction: On manque de données provinciales ou territoriales à long terme publiées et actuelles sur les anomalies congénitales Au Canada. Cette étude fait état de la prévalence (pour 1000 naissances totales) et des tendances pour diverses anomalies congénitales de 1997 à 2019 en Alberta (Canada). Les facteurs de risque associés sont également abordés.

Méthodologie: Nous avons utilisé les données du Système de surveillance des anomalies congénitales de l’Alberta (ACASS) pour calculer la prévalence et effectuer des analyses de tendance linéaire par test du chi carré.

Résultats: Entre 1997 et 2019, la prévalence globale des anomalies du tube neural est demeurée stable, à 0,74 pour 1000 naissances totales. C’était également le cas pour le spina bifida (0,38), les fentes orofaciales (1,99), les cardiopathies congénitales graves (transposition des grandes artères, 0,38; tétralogie de Fallot, 0,33; hypoplasie du coeur gauche, 0,32) et le gastroschisis (0,38). L’anencéphalie, la fente palatine et les anomalies anorectales ont diminué significativement, avec une prévalence de respectivement 0,23, 0,75 et 0,54 pour 1000 naissances totales. Une tendance significativement à la hausse a été relevée pour l’anotie/microtie (0,24), les anomalies de raccourcissement des membres (0,73), l’omphalocèle (0,36) et le syndrome de Down (2,21), ainsi que pour l’hypospadias et la cryptorchidie (respectivement 4,68 et 5,29 pour 1 000 naissances masculines).

Conclusion: Les anomalies congénitales constituent un important problème de santé publique, qui est associé à des coûts sociaux et sociétaux substantiels. Les données de surveillance recueillies par l’ACASS sur plus de 40 ans peuvent servir à la planification et aux décisions en matière de politiques ainsi qu’à l’évaluation des stratégies de prévention. Les facteurs génétiques et environnementaux contributifs sont abordés, de même que la nécessité de poursuivre la surveillance et la recherche.

Keywords: Alberta; congenital anomalies; prevalence; surveillance; trends.

Plain language summary

The Alberta Congenital Anomalies Surveillance System reports prevalence of anomalies and trends from 1997 to 2019 among live births, stillbirths and terminations of pregnancy at less than 20 weeks gestation. Overall prevalence of each of the following was stable, showing no significant trends: neural tube defects, spina bifida, orofacial clefts, cleft lip with or without cleft palate, severe congenital heart defects and gastroschisis. Anencephaly, cleft palate and anorectal malformations show significantly decreasing trends. Anotia/microtia, ventricular septal defects, hypospadias, undescended testes, limb reductions, omphalocele and Down syndrome show significantly increasing trends. Precise risk factors are challenging to address, supporting the need for continued congenital anomalies surveillance and research to be integral to public health.

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Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1. Trend for gastroschisis in Alberta, 1997–2019
Figure 2
Figure 2. Proportion of births to women ≥35 years compared with women <20 years, as a percentage of total births in Alberta, 1997–2019
Figure 3
Figure 3. Trend for omphalocele in Alberta, 1997–2019
See this image and copyright information in PMC

References

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