Close search bar

Small for Gestational Age Rate

This indicator provides the crude rate for small-for-gestational-age (SGA) births.

The in-hospital SGA rate represents the proportion of singleton babies born in a Canadian hospital with a birth weight below the 10th percentile for their gestational age and sex. In other words, babies classified as SGA are smaller than 90% of the babies from a standard reference population of the same gestational age and sex.

Lower rates for this indicator are desirable.

Data updated:
Data availability: to (fiscal years)
Geographic coverage
All provinces/territories
Reporting level
National
Calculation

Rate = (Number of live singleton newborns classified as SGA at birth) ÷ (Number of live singleton newborns with a valid birth weight, gestational age and gender) × 100

Unit of Analysis: Discharges from acute care facilities

Denominator

Number of live singleton newborns with a valid birth weight, gestational age and gender

Numerator

Number of live singleton newborns classified as SGA at birth

Download CSV Expand/collapse all All accordions expanded

Name

Small for Gestational Age Rate

Short/Other Names

SGA

Description

Crude rate for small for gestational age (SGA)

Rationale

SGA rates continue to vary among provinces/territories. Given this variance, this indicator can be used to inform government planners, policy-makers, health system decision-makers, health care providers, patients and the general public. It can help raise awareness and allow Canada to compare its rates with the rates of other countries.

Interpretation

The in-hospital SGA rate represents the proportion of singleton babies born in a Canadian hospital with a birth weight below the 10th percentile for their gestational age and sex. In other words, babies classified as SGA are smaller than 90% of the babies from a standard reference population of the same gestational age and sex.

Lower rates for this indicator are desirable.

HSP Framework Dimension

Health system outcomes: Improve health status of Canadians

Areas of Need

Not applicable

Targets/Benchmarks

Not applicable

Available Data Years

to (fiscal years)

Geographic Coverage

  • All provinces/territories

Reporting Level/Disaggregation

  • National

Indicator Results

Web Tool:
Quick Stats

Update Frequency

Every year

Latest Results Update Date

Updates

As of 2015–2016, the national results include non-residents of Canada.

Description

Rate = (Number of live singleton newborns classified as SGA at birth) ÷ (Number of live singleton newborns with a valid birth weight, gestational age and gender) × 100

Unit of Analysis: Discharges from acute care facilities

Type of Measurement

Rate - Per 100

Denominator

Description:

Number of live singleton newborns with a valid birth weight, gestational age and gender

Inclusions:

  1. ICD-10-CA in-hospital singleton birth code:
    1. A diagnosis code of Z38.0 coded in any position

Exclusions:

  1. Non-newborn records
  2. Cadaveric donors
  3. Invalid birth weight (Weight = blank, 0000, 0001 or ZZZZ)
  4. Invalid or out-of-range gestational age (Delivery Gestational Age = blank or ZZ or <22 weeks or >43 weeks)
  5. Gender Code not equal to F or M
  6. ICD-10-CA multiple births codes: 
    1. Any newborn record (Entry Code = N with a Z38 diagnosis code) where two or more newborn records are born to the same mother (duplicate Maternal Newborn Chart Number) within 40 days of one another (based on Admission Date) in the same institution (Institution Number) OR 
    2. Any one ICD-10-CA multiple birth diagnosis code of Z38.3, Z38.4, Z38.5, Z38.6, Z38.7 or Z38.8 coded in any diagnosis field
  7. ICD-10-CA abortion or other out-of-hospital birth codes:
    1. Any one diagnosis code of P96.4, Z38.1 or Z38.2 coded in any diagnosis field

Numerator

Description:

Number of live singleton newborns classified as SGA at birth

Inclusions:

  1. Weight <10th percentile for gestational age and gender category. Standard Canadian birth weights for gestational age by gender charts were used (M. S. Kramer et al., 2001).

Exclusions:

Same as denominator (numerator is a subset of the denominator)

Method of Adjustment

Not applicable

Adjustment Applied

None

Geographic Assignment

Place of residence

Data Sources

  • DAD

Caveats and Limitations

In order to provide a more stable rate estimate, only data from regions with a population of at least 50,000 was reported. Additional reasons for suppression were privacy, rate instability and under-reporting. As of 2015–2016, regions are not suppressed based on population; instead, the following suppression methodology is used:

  1. Suppression due to privacy: To ensure privacy, a suppression rule is applied to all clinical indicator results. Numerators and/or denominators between 1 and 4 are suppressed.
  2. Suppression due to unstable results: Unstable indicator results are suppressed. In general, these are indicator results with a denominator between 1 and 49.

Trending Issues

Refer to the Important notes in Hospitalization and Childbirth Quick Stats Metadata (PDF)

Comments

For more information about this indicator, please refer to Hospital stays in Canada.

References

Kramer MS, Platt RW, Wen SW, et al. A new and improved population-based Canadian reference for birth weight for gestational age. Pediatrics. 2001;108(2):e35.

How to cite:

Canadian Institute for Health Information. Small for Gestational Age Rate. Accessed April 24, 2025.