A new Canadian study has said that expectant mothers consuming prescription drugs are at an increased risk of suffering miscarriage or give birth to kids with major congenital abnormalities.

"I never expected such results and I was extremely surprised," said senior author Anick Berard, a professor at the Universite de Montreal's Faculty of Pharmacy and director of the Research Unit on Medications and Pregnancy of the Sainte-Justine University Hospital Centre.

The data from the Quebec Pregnancy Registry on 109,344 women, aged 15 to 45 revealed that 6,871 pregnant women consumed one of 11 prescription drugs that are known to be harmful to fetuses through the first, second or third trimester.

Of those women, 3,229 aborted; 6 percent had a miscarriage; and 8.2 percent gave birth to a child with major congenital malformations.

The study also examined the use of prescription drugs that are known to be feto-toxic or increase in-utero problems or premature births.

The researchers found that 11,400 prescriptions - for dangerous medicines such as isotretinoin (for the treatment of acne and rosacea), anxiolytic benzodiazepines (anti-anxiety treatment) and antiepileptics (epileptic seizure treatment) - were used by pregnant women.