Antidepressants during pregnancy: Worth the risk?

"These results raise many interesting questions, and there are many things we still don't know," says Samantha Meltzer-Brody. "What we do know is that untreated depression can be very harmful for women and their babies, and so we strongly encourage pregnant women who are being treated for depression to continue with their treatment." (Credit: Sarah Gilbert/Flickr)

A recent study suggests taking a certain class of antidepressants during pregnancy may increase the risk of a brain malformation for children. Even so, researchers say doctors shouldn’t change their prescribing practices based on the results.

The antidepressants in question are called selective serotonin reuptake inhibitors (SSRIs), and the brain malformation is known as Chiari type 1, condition in which brain tissue in the cerebellum (a part of the brain that controls balance, motor systems, and some cognitive functions) extends into the spinal canal.

About 5 percent of children have a Chiari type 1 malformation. Most do not have any problems because of it, but some develop symptoms such as headache and balance problems. In severe cases surgery may be necessary.

“Our results can be interpreted two ways,” says lead author Rebecca Knickmeyer, assistant professor of psychiatry in the UNC School of Medicine and lead author of the study.

“Either SSRIs increase risk for Chiari type 1 malformations, or other factors associated with SSRI treatment during pregnancy, such as severity of depression itself, increase risk. Additional research into the effects of depression during pregnancy, with and without antidepressant treatment is urgently needed.”

Details of the study

For the study, published in the journal Neuropsychopharmacology, MRI brain scans of 33 children whose mothers were diagnosed with depression and took SSRIs, such as sertraline and fluoxetine, were compared to scans of 66 children whose mothers had no history of depression.

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In addition, 30 children whose mothers were diagnosed with depression but did not take SSRIs were compared to 60 children whose mothers had no history of depression.

Eighteen percent of the children whose mothers took SSRIs during pregnancy had Chiari type 1 malformations, compared to 3 percent among children whose mothers had no history of depression.

The rate of Chiari type 1 malformations was highest in children whose mothers reported a family history of depression in addition to treatment with SSRIs during pregnancy, suggesting an important role for genes as well as environment. Duration of SSRI exposure and SSRI exposure at conception also appeared to increase risk.

Risks and benefits

“These results raise many interesting questions, and there are many things we still don’t know,” says study coauthor Samantha Meltzer-Brody, associate professor of psychiatry. “For example, we do not know how many of these children will go on to develop symptoms of Chiari type 1 malformations.

“What we do know is that untreated depression can be very harmful for women and their babies, and so we strongly encourage pregnant women who are being treated for depression to continue with their treatment,” she says.

A decision to use antidepressants during pregnancy must be based on the balance between risks and benefits and that it is critical that health care providers and the public get accurate information on this topic, says Knickmeyer.

She also notes that a diagnosis of Chiari Type 1 is often delayed due to the non-specific nature of the symptoms. Thus, it may be valuable for families in this situation to know about the results of this study.

“Chiari type 1 malformations are somewhat common, but very little is known about what causes them,” says study coauthor J. Keith Smith, professor and vice chair of clinical research in UNC’s radiology department. “Studies like this could give us new insight into that question.”

Source: UNC-Chapel Hill