The site includes a personalized quit meter, various self-help materials, tips on having a healthy pregnancy, and partner support.
Surveys show that about one in 10 Canadian women smoke while pregnant. But Dr. Peter Selby said it's likely the proportion of women continuing to use tobacco during gestation could be as high as 30 per cent, depending on the population segment being studied.
The goal of PREGNETS is to help women overcome their addiction or to at least significantly cut down the amount they smoke, though Selby stressed "there is no safe amount of smoke exposure while pregnant."
"It is dangerous to both the woman and the fetus. It's not just the fetus," he said Thursday.
A woman who smokes during pregnancy puts herself in danger of miscarriage, as well as risking other well-documented conditions like cancer and cardiovascular disease.
"The risk to the fetus is an immediate risk," said Selby, clinical director of CAMH's addictions program. "They're much more likely to be premature, likely what we call small for gestational age, and then they have a higher risk of things like sudden infant death syndrome and upper respiratory tract infections."
As children, the offspring of mothers who smoked while pregnant are also more likely to develop behavioural problems and are at increased risk for obesity in adolescence, studies suggest.
Selby said providing an online quitting tool is meant to help women overcome the stigma associated with smoking while pregnant.
While experiencing society's censure can provide the impetus for some women to kick the habit, it can also lead to an unwanted result, he said.
"The problem is if you're addicted, a couple of things happen: you go underground, you become a closet smoker. You don't seek out help because you feel you'll get judged.
"And you're going through a pregnancy - which should be a nice, happy time - feeling guilty and trapped and worrying what the outcome might be."
Experts have long pointed out that being hooked on tobacco is one of the most complex and difficult addictions to overcome.
"It's not that simple to just stop, no matter what the compelling reasons are," including having had a heart attack or an organ transplant, he said. "It's the nature of an addiction that people, despite wanting to, cannot stop."
Selby said society tends to "pick on mothers," when in fact partners and other family members who use tobacco also contribute harm by exposing the pregnant woman and consequently her fetus to second-hand smoke.
"The father could be doing whatever he wants while the woman's pregnant, but that doesn't get counted," he said. "It's not just her problem. It's an issue for both to address."
In a section on partner support, the website advises: "When you are quitting or reducing smoking, it helps to get support from the people around you. Women tend to find it harder to quit or cut back when their partner and others who are close to them smoke."
PREGNETS also provides up-to-date evidence-based information on smoking and quitting for health-care practitioners that can be shared with patients, he said.
"Not a lot of professionals know what to do. There's a lot of misinformation. Some say: 'Don't quit smoking because it's too stressful for the baby.' That's a myth," said Selby, but one that seems to be perpetuated worldwide.
Still, PREGNETS isn't about only "dry knowledge or facts" - it's about women having a forum for exchanging ideas and finding encouragement from peers battling their own nicotine addictions, he said.
"The anonymity the Internet provides could potentially provide a place for women who may be very isolated but have access to the Internet to get information and share their ideas and thoughts and feelings and worries and fears, without the risk of being judged," Selby said.
"Now there's a space where if you're not comfortable telling your health-care provider or your family or whomever, it doesn't mean you're alone."
As one discussion participant posted recently: "None of my friends smoke and when I talk to them about it I feel like they just don't get it. I haven't set a quit date yet but I hope to soon. I feel like I need to get a bit more motivated first ... hoping this site will help in that department."