Birth weight is
considered one of the most important indicators of a newborn’s chances of
survival. Low or high birth weights are important public health indicators as
they occur with greater prevalence in disadvantaged populations.
A newborn is
small for gestational age if weighing 500-2499 grams immediately at birth. A newborn
is large for gestational age if weighing 4,500 grams or more immediately upon
birth.
In Canada, 6.2% of
babies were born small for gestational age and 1.7% of babies were born large
for gestational age in 2012. The proportion of babies born average weight was
92.2% in 20121
Small for gestational age
(SGA)
Babies that are
born small for gestational age (SGA) are singleton births that have a weight
below the 10th percentile for their gestational age and sex. An SGA baby weighs less than 90% of babies of
the same gestational age and sex in a reference Canadian cohort of singleton
births.
Between 2009 and
2014, 367 out of 5,454 singleton live births in the NWHU area were SGA, which
equals a proportion of 6.73%. This is
lower and statistically different from the provincial proportion of 9.22% over
the same time period
Figure 1: Small for gestational age (SGA) rates,
2009-2014
Source: Inpatient Discharges 2005-2014, IntelliHEALTH
Ontario, Ontario Ministry of Health and Long-Term Care, Date Extracted: January
15, 2016
Figure 2: Small for gestational age (SGA) rates in the
NWHU by municipality, 2009-2014 combined
Source: Inpatient Discharges
2005-2014, IntelliHEALTH Ontario, Ontario Ministry of Health and Long-Term
Care, Date Extracted: January 15, 2016
Looking at
maternal age groups for SGA births between 2002 and 2011, rates are fairly
similar across all ages, ranging from about 4.7% in 15-19 year-olds to 6.3% in
25-29 year-olds (the differences are not statistically significant).
Figure 3: Small for gestational age (SGA) rates in the
NWHU by age group, 2002-2011 combined
Source: Ontario Vital Statistics Live Birth Data 2002-2011, Ontario
Ministry of Health and Long-Term Care, IntelliHEALTH Ontario, Date Extracted:
February 24, 2015
Large for gestational age (LGA)
Babies that are
born large for gestational age (LGA) are singletons that weight more than 90%
of babies of the same sex and gestational age in the Canadian reference cohort.
Between 2009
and 2014 there were 5,454 singleton live births in the NWHU area, and 867 of
them were LGA. This equals an LGA rate
of 15.9% over this time period which is nearly 1 out of 6 live births. Over the same time period, the LGA rate
provincially was 10.3%, which is statistically lower than the rate in the NWHU
area.
Source: Inpatient Discharges 2005-2014, IntelliHEALTH
Ontario, Ontario Ministry of Health and Long-Term Care, Date Extracted: January
15, 2016
Source: Inpatient Discharges 2005-2014, IntelliHEALTH
Ontario, Ontario Ministry of Health and Long-Term Care, Date Extracted: January
15, 2016
Looking at
combined LGA rates from 2009 to 2014, Sioux Lookout had the highest rate at
20%, or 1 out of 5 babies that were large for their gestational age. This rate is statistically higher than the
rates in Kenora, Dryden and Fort Frances, and is also statistically higher than
the all-municipality combined rate of 14.2% over this time period. Dryden’s LGA rate of 10.3% is statistically
lower the all-municipality rate.
Figure 5: Large for gestational age (LGA) rates in the
NWHU by municipality, 2009-2014 combined
Source: Inpatient Discharges 2005-2014, IntelliHEALTH
Ontario, Ontario Ministry of Health and Long-Term Care, Date Extracted: January
15, 2016
Between 2002 and 2011
there were slight variations in the LGA rates in different age groups, but
there were no statistical differences.
Figure 6: Large for gestational age (LGA) rates in the
NWHU by age group, 2002-2011 combined
Source: Ontario Vital Statistics Live Birth Data 2002-2011, Ontario
Ministry of Health and Long-Term Care, IntelliHEALTH Ontario, Date Extracted:
February 24, 2015
References
1 Statistics Canada. (2016). Live births by birthweight and sex, Canada,
provinces and territories. Retrieved from http://www5.statcan.gc.ca/cansim/a21/