Pregnancy and Antidepressants: Small Risk of Birth Defects

Ivanhoe Newswire
Thursday, June 28, 2007; 12:00 AM

By Vivian Richardson, Ivanhoe Health Correspondent

ORLANDO, Fla. (Ivanhoe Newswire) -- When women being treated for depression get pregnant, worries of fetal harm may convince them to stop taking antidepressants. Two studies reveal the risk of birth defects is virtually non-existent, except in the case of a few selective serotonin-reuptake inhibitors (SSRIs).

Researchers from Boston University's Slone Epidemiology Center report the SSRIs they tested do not appear to increase the risk for most kinds of birth defects. However, they discovered setraline (Zoloft) could be linked to omphalocele (where intestines or other abdominal organs protrude from the naval) and septal defects (defects in the walls that separate the chambers of the heart). They also linked paroxetine (Paxil) to certain heart defects that interfere with blood flow to the lungs.

"I don't think it's really something to be alarmed about," lead author Carol Louik, Sc.D., an assistant professor at the Slone Epidemiology Center at Boston University, told Ivanhoe. "I think our study is more reassuring than alarming, but we can't lose sight of the fact that there were some associations and we can't dismiss those."

Approximately 3 percent of all pregnant women take an SSRI in their first trimester, explained Dr. Sloan. Knowing how the drug may affect their fetus, no matter how small the risk, is important, she said.

Previous studies have suggested SSRIs do not increase the overall risk of birth defects. However, Dr. Sloan and her colleagues wanted to know if individual medications would have influences on individual defects.

"Birth defects are not a single outcome. They all have distinct etiologies; they arise for different reasons in the body," Dr. Sloan said. Also, despite being a part of the same class of drugs, individual SSRI medications are each metabolized by the body differently, she explained.

Researchers used data from an ongoing program studying the relationship between medication use and birth defects. They compared first trimester SSRI use and the risk of various birth defects among mothers of 9,849 infants with birth defects and 5,860 infants without defects.