Pregnant women in Alberta had a higher rate of smoking than the national average, with as many as a third of current — or former — smokers in the province taking up the habit while they were expecting, according to a new study.

The research was done from January through to December 2005. A total of 28,484 samples were randomly selected from a larger group of more than 44,500 samples gathered from across the province.

"This is the first province-wide bio-monitoring study for Alberta, and few other studies are currently available from elsewhere in Canada," noted the report, which was posted this month on the Alberta Health website.

And, despite numerous reports and warnings about the dangers of smoking during pregnancy, the report found that in Alberta the habit either persisted — or resumed — while women were expecting.

"In Alberta, approximately one-fifth (22.8 per cent) of the population smokes," the report said.

Increase during childbearing years

"Unfortunately, the rate of smoking among women increases during childbearing years (between 15 and 44 years of age). In Alberta, approximately 25-32 per cent of current or former female smokers (ages 15 to 55) smoke, or smoked, regularly during their most recent pregnancy," the report said.

The rate in Alberta was higher than the national average of 19-22 per cent, the report noted.

Smoking habits have persisted in the province despite several government initiatives, the report said. Those measures included a 2002 plan to reduce smoking rates in pregnant women in the province to 12 per cent in 2010-2011 from 32 per cent in 2000-2001 .

As well, at the start of 2008, Alberta approved a province-wide smoking ban in all public places and workplaces.

Despite these measures, the report noted, pregnant women were smoking and in doing so were exposing themselves and their fetus to a host of negative effects.

"In general, the developing fetus is the most sensitive human life-stage and can be exposed to chemicals that cross the placenta," the report said.