An investigation by the Toronto Star suggests that a drug product prescribed to pregnant women for morning sickness may be linked to birth defects. The newspaper claims that Health Canada is aware that the product has serious side-effects but has taken no action to prevent further harm.

According to the Star, the drug ondansetron is quite powerful and is approved by Health Canada as a therapy for nausea and vomiting that occur as a result of chemotherapy and surgery. It has never been approved to treat morning sickness in pregnant women. However, some doctors prescribe it "off label" without having any evidence that the drug is safe for expectant mothers and their babies.

After analyzing birth records from 2012, the Star said it had identified at least 20 cases in which pregnant women treated with ondansetron suffered serious consequences — two of the babies died and many of them were born with kidney malformations and heart defects.

But the Toronto Star also revealed that ondansetron was not the only drug prescribed for off-label uses on a regular basis in Canada. In fact, Health Canada agreed to share limited information with the newspaper, suggesting that approximately 20 drugs were prescribed in such ways. There is no regulation that bans doctors from prescribing drugs off label and there is no oversight on what they actually prescribe to patients, the Toronto Star said.