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About Sickkids
About SickKids

April 2, 2008

Use of antidepressant drug paroxetine in early pregnancy does not increase risk of cardiovascular birth defects

TORONTO – No association has been found between the use of the antidepressant paroxetine in the first trimester of pregnancy and an increased risk of heart defects in exposed infants according to a study conducted by researchers at The Motherisk Program of The Hospital for Sick Children (SickKids), and the University of Toronto. Their findings are published online today in the American Journal of Psychiatry.

Commonly used to treat depression as well as obsessive-compulsive disorder, anxiety disorders, and premenstrual dysphoria, paroxetine, is mostly prescribed under the brand name Paxil®.

Motherisk partnered with centres from around the world that study and provide information on the safety of medication in pregnancy to follow up on 1,174 women in Canada, the US, Australia, Italy, Switzerland, Germany, Finland, and Israel who called such centres with regard to the use of the drug in early pregnancy (when the fetus' heart develops). Data was then compared with the outcomes of an equal sized group of non-exposed infants. The rate of cardiovascular defects was 0.7 per cent in each group. As the incidence of heart defects in the general population is approximately one per cent, the rates in this study were slightly lower than expected.

An additional 2,061 cases were reviewed from previously published database studies that examined pregnancy outcomes following exposure to the drug. The rate in this group was 1.5 per cent, and when the two sets of data were combined, the mean rate of cardiovascular defects was 1.2 per cent. These data represent the largest number of exposures to paroxetine during the first trimester of pregnancy ever documented.

“In recent years, there have been a number of conflicting studies concerning the safety and or risk of antidepressant use during pregnancy,” says Adrienne Einarson, assistant director of the Motherisk Program and the study's lead author. The number of related calls at Motherisk has also increased dramatically. “We hope that this information will enable health care providers to make informed recommendations to their patients, who will then have the peace of mind that comes from making an evidence-based decision as to whether or not to take this drug during pregnancy.”

According to published research, twice as many women as men experience depression. Up to 20 per cent of women who are of child bearing age are diagnosed with the disease and 10 to 15 per cent of women with depression experience it during pregnancy.

“Given that up to 50 per cent of pregnancies are unplanned, we were concerned that women who were taking paroxetine would abruptly discontinue their medication upon discovering that they were pregnant, for fear of harming their babies,” explains Einarson. “Women are encouraged to discuss their options with their health care providers, yet no clinical practice guidelines exist in Canada for the treatment of depression during pregnancy, particularly with regard to whether or not to take an antidepressant.”

Studies have shown that untreated depression in pregnancy carries substantial risks to the fetus and infant such as increased risk for miscarriage, hypertension, pre-eclampsia, and lower birth rate, as well as risks secondary to unhealthy maternal behaviours such as suicidal ideation, and a six-fold increase for postpartum depression. “A pregnant woman should always be in the best state of mental health possible to ensure optimal outcomes for both herself and her child,” adds Einarson.

The Motherisk Program at Sick Kids has been providing counseling and research about the safety or risk to the developing baby of maternal exposure to drugs, chemicals, diseases, radiation and environmental agents for more than 20 years. Since it was created in 1985, Motherisk has counseled more than 250,000 women. It is the only program of its kind in Canada and one of the most comprehensive in the world.

The Hospital for Sick Children (SickKids), affiliated with the University of Toronto, is Canada 's most research-intensive hospital and the largest centre dedicated to improving children's health in the country. As innovators in child health, SickKids improves the health of children by integrating care, research and teaching. Our mission is to provide the best in complex and specialized care by creating scientific and clinical advancements, sharing our knowledge and expertise and championing the development of an accessible, comprehensive and sustainable child health system. For more information, please visit www.sickkids.ca . SickKids is committed to healthier children for a better world.

For more information, please contact:

Janice Nicholson
Public Affairs
The Hospital for Sick Children
Phone: 416-813-6684
Fax: 416-813-5328
email: janice.nicholson@sickkids.ca