Teenage mothers were far less likely to have two or more children in 2003 than they were ten years prior, Statistics Canada reported Wednesday.
An estimated 25,000 teenaged moms gave birth to their second or subsequent child between 1993 and 2003, the government agency said.
The rate of teen moms who had two or more children fell by one-half during the ten-year timeframe, the study showed.
In 1993, of every 1,000 girls aged 15 to 19 who had already had a child in 1993, 4.8 of them had a second or subsequent birth. By 2003, this rate was down to 2.4.
"Fertility rates have been declining among teenage girls almost steadily since the mid-1970s," Statistics Canada said in the report.
By 2003, the rate of live births to girls aged 15 to 19 was only about one-seventh the rate for women aged 25 to 34.
The study also found that teens with two more children were highly concentrated in low-income neighbourhoods.
Half the 15- to 19-year-olds who had a second or subsequent child in the 2001-to-2003 period lived in communities that were in the lowest fifth of the neighbourhood income distribution.
In contrast, women aged 25 to 34 who had a second or subsequent child in that period were fairly well distributed across the income groups.
"As well, the education and employment opportunities of the teens who have babies are often curtailed," Statistics Canada said in its report.
"Consequently, young mothers and their children are likely to be economically disadvantaged."
Furthermore, the proportion of second or subsequent babies who were born at a low birth weight -- less than 2,500 grams -- was significantly higher for teen moms than for those aged 25 to 34.
Among the teen moms, 6.1 per cent had second or subsequent babies who were born at a low birth weight. In contrast, the same was true for 3.7 per cent of their counterparts aged 25 to 34.
"A newborn's chances of survival are closely associated with birthweight," Statistics Canada.
"Those who weigh less than 2,500 grams at birth have higher mortality and more physical health problems than babies whose weight at birth was normal."
The rate of second or subsequent births among teenagers varied across the country.
The national average of teen moms who have had second or subsequent births is 2.6 of 1,000 girls.
Between 2001 and 2003, the rate in Nunavut was 12 times the national average with 31.9 girls out of 1,000.
The rate was nearly three times the national average in Manitoba, with 6.8 of 1,000; and also in Saskatchewan with 6.3 of 1,000.
Rates were below the national average in Nova Scotia, Quebec and British Columbia.
"Provinces and territories with high rates of second or subsequent births to teens tended to have relatively large numbers of Aboriginal residents," Statistics Canada reported.
In 1999, more than one in 5 First Nations babies were born to mothers aged 15 to 19, whereas the comparable figure for Canada as a whole was one in 20.
The data used in the study covered all provinces except for Ontario.
Ontario introduced birth registration fees in 1996, and an estimated 3 per cent of all births in that province may not have been registered since then, Statistics Canada said.
This is particularly likely for children born to teenage mothers and babies who died within days of birth, the agency said.
