Fertility Rates

This report examines trends in general, age-specific and total fertility rates in KFL&A and Ontario between 2003 and 2013. Fertility is a measure of the number of children born in relation to the number of women of reproductive age within a population.¹  Reproductive age is usually considered to be between 15 and 49 years of age.  The general fertility rate (which is a ratio of the number of live births in a given time period to the female population of reproductive age) is examined first since it is a commonly used measure of fertility.²  It should be noted that comparing general fertility rates across populations or within a population over time may provide misleading implications since rates do not consider differences in the age structure of populations.  Thus, age-specific fertility rates are often used to account for the age structure of populations and can be presented alongside general fertility rates for more complete information.

To better understand how fertility rates may be changing, and among which groups, trends are often examined by various socio-demographic characteristics.  For example, fertility rates are often investigated by age to gain an improved understanding of how rates differ between women of varying age groups.  Age-specific fertility rate is most often used to investigate such trends, and is a measure of the number of live births born to women in a specific age group,² relative to the number of women in the population within that age group.  The age at which women first have children has increased over recent years.³  In the early 2000's, women aged 20 to 24 years had the highest fertility rates; this trend has since shifted, with those aged 30 to 34 now having the highest fertility rates.³  

Figure 1. General fertility rates per 1,000 females aged 15 to 49 years, KFL&A and Ontario, 2003-2013^4-6

Interpretation for Figure 1:

Figure 2. Age-specific fertility rates per 1,000 females aged 15 to 49 years, KFL&A and Ontario, 2012-2013⁽⁵⁾

Interpretation for Figure 2

Figure 2 shows the age-specific fertility rates for both KFL&A and Ontario (rates not shown for ages 45-49 due to small numbers).  Mothers aged 30-34 have the highest fertility rates for both KFL&A and Ontario.  Ontario shows slightly higher fertility rates in those aged 30-34 and 35-39 than KFL&A. The highest fertility rates are seen among women aged 30 to 34, and 25 to 29, respectively, in both KFL&A and Ontario. These rates are consistent with the trends seen in Canada over the past ten years.³  Among women aged 25 to 29 in Canada, fertility rates have fallen in recent years from 255.9 births per 1,000 women in 1959 to 92.5 births per 1,000 women in 2011.⁷  In about 2005, the fertility rates of women in Canada aged 30 to 34 began to surpass those of women aged 25 to 29.  The fertility rate of women aged 35 to 39 has tripled since the 1970s, and is now higher than the rates of those aged 20-24. Changes in fertility trends are reflective of the changes that have occurred in our society -particularly around women often delaying childbirth in pursuit of higher levels of education and labour force participation. 

Figure 3. Age-specific fertility rates per 1,000 females aged 15 to 49 years, KFL&A, 2003-2013⁽⁵⁾

Interpretation for Figure 3

Figure 3 displays the age-specific fertility rates in KFL&A from 2003 to 2013. Over time, it seems the age-specific fertility rates for those aged 30-34 have increased slightly, as well as for those aged 35-39. These findings are consistent with recent trends seen in Canada.³  

Total fertility rates in Canada have been low in recent years. The total fertility rate is the number of children that a woman would have over the course of her reproductive life if she experienced the age-specific fertility rates observed in a particular calendar year.⁷ Fertility rates peaked in the 1950's with 3.93 children per woman in 1959, and have declined since, reaching an all time low of 1.49 children per woman in 2000.¹  In Canada in 2011, the total fertility rate was 1.6 children per woman, which has since declined over the previous four years.⁷  In 2013, the total fertility rate in KFL&A was 1.3 children per woman, and in Ontario was 1.4 children per woman.⁴  The decline in total fertility rate is mainly due to a steady decline in age-specific fertility rates in age groups under 30.  In contrast, the fertility rates for mothers over 30 have increased.⁷

For a complete list of data sources and terms used in the Reproductive Health Facts & Figures, see the Facts & Figures titled "Data Sources for Reproductive Health" and "Glossary for Reproductive Health" located on the Facts & Figures webpage in the Reproductive Health section.

1. Human Resources and Skills Development Canada. Canadians in Context: population size and growth, indicators of well-being in Canada. Employment and Social Development Canada 2014 [cited 2014 Nov 14]
2. APHEO Core Indicators. Fertility rates. 2012 [cited 2014 Nov 20]
3. Statistics Canada.  Age-specific fertility rates, Canada, 1989 to 2009.  2014 [cited 2014 Nov 20]
4. BORN Information System: (Fiscal years: 2012-2013). [extracted 2014 Oct 31]
5. Inpatient Discharges: (Calendar years: 2000-2013). Ontario Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO.  [extracted 2014 Oct 31]
6. NIDAY Database: (Calendar years: 2003-2011)
7. Anne Milan. Fertility: Overview, 2009 to 2011. 2013 Statistics Canada