Women who take certain anti-inflammatory medications could be prone to a higher risk of miscarriage, a new Quebec study suggests, but at least one doctor is already disputing the research.

The study, which appears in the Canadian Medical Association Journal, examined pregnant women and their use of prescribed non-aspirin, non-steroidal anti-inflammatory drugs, also known as NSAIDs.

Those drugs include naproxen, ibuprofen, diclofenac and celecoxib.

The study obtained its data from the Quebec Pregnancy Registry and the Quebec insurance plan RAMQ. It found that the risk of miscarriage was 2.4 times greater for women prescribed with NSAIDs.

Dr. Gideon Koren, director of the Motherisk program at the Hospital for Sick Children in Toronto, told The Canadian Press the study is flawed because one of the drugs -- ibuprofen -- is available without a prescription.

"The ibuprofen is a huge part and we don't know who bought it or not, and who took it, if the group that did not have miscarriages bought it more than the other group," he said Tuesday in an interview.

"You cannot use a prescription database for a drug which is given not just for prescription. It just doesn't jibe."

Researchers studied 4,705 cases of women who suffered miscarriages, along with a control group of 47,050 who did not miscarry. In the first group, 7.5 per cent had been prescribed a non-aspirin NSAID. In the control group, it was 2.6 per cent of women.

Anick Berard, who co-authored the study, said researchers found that women appeared to have an increased risk of miscarriage no matter which NSAID they used.

"I think that NSAIDs -- because the majority of the use is for pain and migraine headache, for example -- I think that women can very well go ... at the beginning of their pregnancy without these drugs," she told The Canadian Press.

But Koren said women might use NSAIDs before they know they're pregnant, while others might need a NSAID to treat a specific condition.

"If a woman has very severe rheumatoid arthritis and without taking naproxen or any of the others, she cannot function, she's very different from a woman who has once in a while a headache," he said.

"And then they're both very different from a woman with migraine headaches who may not be able to be in class as a teacher if she's not controlling (the pain). So the answer clearly cannot be based on this study. This study is too flawed."

In light of the debate, CTV medical specialist Avis Favaro notes that pregnant women who suffer from chronic pain, arthritis or conditions like lupus may still have some treatment options.

Products using acetaminophen might be the best option, she said.

"The study didn't find this sort of boosted risk with acetaminophen-type products, so that would be your Tylenol. Those appear to be, in this case, safe."

With a report from CTV medical specialist Avis Favaro and producer Elizabeth St Philip