Congenital Anomalies in Canada:

About congenital anomalies

Congenital anomalies are the leading cause of infant mortality in Canada.¹ They can have long-term impacts on individuals, families and healthcare systems. Congenital anomalies are an important public health issue.

Congenital anomalies are present at birth. They may affect the structure of the body or how it functions.² Congenital anomalies are also known as birth defects, congenital disorders or congenital malformations.²

• They may be identified during pregnancy, at birth, or later in life.
• Approximately 50% of all congenital anomalies cannot be linked to a specific cause.²
• Known risk factors include genetics and environmental factors such as:
  • exposure to radiation or certain pollutants
  • maternal infections
  • nutritional deficiencies²
• Not all congenital anomalies have long-term effects. Many people have congenital anomalies without significant impact on their lives.

Data exploration tool and sources

Surveillance activities are a core function of the Public Health Agency of Canada (PHAC). Through surveillance, we collect, monitor and analyze health data. Our goal is to better understand public health issues, including congenital anomalies. The data can inform prevention strategies and healthcare system planning.³ This can ultimately help reduce infant mortality and improve infant health.³

The data exploration tool presents data from the Canadian Congenital Anomalies Surveillance System (CCASS). The tool provides prevalence estimates and data trends for 38 congenital anomalies in Canada. It was updated using data from:

• the Discharge Abstract Database of the Canadian Institute for Health Information
• the Quebec congenital anomalies program, which uses the Maintenance et exploitation des données pour l'étude de la clientèle hospitalière (MED-ÉCHO)

Quick facts

Age at the time of pregnancy can be a risk factor for some congenital anomalies:

• when maternal age is less than 25 years old, the infant has a higher risk of limb deficiencies and abdominal wall defects
• when maternal age is over 35 years old, the infant has a higher risk of chromosomal anomalies and congenital heart defects

Infants with a congenital anomaly are 3 times more likely to be born preterm (before 37 weeks) compared to infants without a congenital anomaly.

In Canada, the most common cases of congenital anomalies are:

• undescended testes
• congenital heart defects
• Down syndrome

Overall, congenital anomalies occur more frequently in males than females. Some congenital anomalies are sex specific:

• Turner’s syndrome occurs in female infants
• hypospadias and undescended testes occur in male infants

Babies born with a congenital anomaly require more care:

• 25% of infants born with congenital anomalies require re-admission to hospital in their first year of life (compared to 8% of infants without congenital anomalies)
• the average hospital stay at birth is 17 days (compared to 3 days for infants without a congenital anomaly)

Approximately 5% of all infants with a congenital anomaly will die within their first year of life.
Rarer anomalies tend to be more severe and can be life-threatening. Neural tube defects are rare anomalies. They have the highest fatality rate among congenital anomalies. In contrast, undescended testes is the most common anomaly and does not lead to death.

Neural tube defects are a type of congenital anomaly that affect the brain, spine or spinal cord. Public health strategies, like folic acid fortification and supplementation, help prevent these defects.⁴