The report is based on data from the 2009-2010 Canadian Community Health Survey, which is the first national population-based questionnaire to ask respondents about the use of assisted reproductive techniques.
Co-author Suzanne Tough, an epidemiologist in maternal and child health at the University of Calgary, said the report's findings are not surprising.
"I think it's what we're seeing in many developed countries, so the 15 per cent of couples having challenges conceiving is not uncommon in 2012 or in the current landscape," Tough said Wednesday from Calgary.
In 2009-2010, about 380,000 Canadian couples turned to doctors for help when the woman was unable to get pregnant, the federal report shows.
Age was a big factor in that decision: data show couples in which the woman was aged 35 to 44 were two to three times more likely to seek help than were couples in which the woman was 25 to 29.
The survey also found childless couples were four to five times more likely to seek medical assistance than were those with at least one child.
A growing number of couples in Canada are delaying childbirth. Since 1984, the percentage of first-born children with mothers aged 35 or older has tripled to 11 per cent, the report says.
Tough said the ability to conceive diminishes for both men and women as they age, and the statistics bear that out in higher numbers of women in the last decade of their child-bearing years being more likely to seek medical assistance to get pregnant.
Among couples unable to conceive, about two in five reported turning to fertility-enhancing drugs, while one in five said they used assisted reproductive techniques, or ART.
But behind the numbers is a "whole under-story," said Tough. "I think that people don't realize what they're trading off. They don't recognize that waiting an extra three or four years (to become parents) ... could make things more complicated than they thought.
"They think, 'Oh, I can wait until 35 because I'll just go for ART.' But people often underestimate the probability of success with reproductive technologies like in vitro fertilization," she said.
When a woman is 35 to 39, the chance of conceiving per cycle with ART is 28 per cent, and just 11 per cent for women age 40 and over, explained Tough. Even for younger women, the overall success rate is only 40 per cent.
She said it's difficult to get that reality-check message across when magazines trumpet the news of aging celebrities having babies, among them singer Celine Dion having twins at 42 and actress Geena Davis getting pregnant at 48.
And if an older would-be mom does conceive, the pregnancy can often be a bumpier ride than most younger women would experience.
"Women over 35 are more likely to have complications during pregnancy, like high blood pressure and gestational diabetes, compared to younger women," Tough said. "And they're also more likely to deliver babies pre-term or low birthweight."
Older mothers-to-be also have a higher risk of miscarriage than their younger counterparts.
Not only women's fertility is affected by age: studies suggest that men's sperm quality decreases over time. "So men over the age of 40 are also more likely to have problems conceiving and there's some evidence that there's an increased risk of congenital anomalies (in offspring) as men age," she said.
Infertility in Canada is becoming more common: In 1984, the prevalence of infertility was five per cent; in 2009-2010, that figure had risen to 12 to 16 per cent.
Statistics Canada can't say whether the use of assisted reproductive techniques is increasing at the same time, as the 2009-2010 survey was the first national population-based look at its prevalence.
However, the Canadian Assisted Reproduction Technologies Register shows the number of annual procedures performed has risen steadily over the last decade.
The report's authors suggest this upward trend could continue, particularly if more provinces start providing coverage for the cost of treatments, as is the case in Quebec.Suggest a correction