Updated Sunday, Apr. 05, 2009 2:04 AM EDT

Health Canada has issued a warning for women taking antidepressants drugs known as selective serotonin re-uptake inhibitors – drugs such as Prozac and Paxil – and who are pregnant or thinking of becoming pregnant.

The advisory was an attempt to draw attention to a recent study linking SSRIs, as they are called, to a condition called persistent pulmonary hypertension in babies born to women who took the drugs during the second half of their pregnancies.

The department urged women to discuss the issue with their doctors, but stressed that they should not stop taking their medication without first consulting a physician, because they risk experiencing serious side-effects.

“Newborns with this rare but life-threatening condition do not receive enough oxygen in the blood and require intensive-care treatment to survive,” the advisory noted.

“According to the study, babies born with this condition were six times more likely than healthy babies to have been exposed to SSRIs. This information is considered to be preliminary at this time.”

Drugs mentioned by the department were: Wellbutrin (bupropion); Celexa (citalopram); Cipralex (escitalopram); Prozac (fluoxetine); Luvox (fluvoxamine); Remeron (mirtazapine); Paxil (paroxetine); Zoloft (sertraline). Also mentioned were Effexor (venlafaxine) and Zyban (bupropion), which are prescribed for smoking cessation.

The advisory said SSRI treatment should only be continued if benefits to the patient are thought to outweigh risks to the fetus, adding that there have been numerous reports in Canada and abroad indicating that some children exposed to SSRIs and other newer antidepressants during pregnancy may develop serious complications at birth.

“An increase in the overall risk of major birth defects has also been associated with SSRI use,” the statement noted.