Pregnant woman in hospital gown rubs her belly.
Pregnant woman in hospital gown rubs her belly.

Pregnancy is a time of great change and, for many women, great joy.  But for other expectant mothers, the added stress, along with physical and hormonal changes, increases the risk of clinical depression.  

Many women who suffer from depression in the period just before conceiving often give up their medications, at the recommendation of their obstetricians.

The reason: In the past there have been conflicting studies, some that link selective serotonin reuptake inhibitors (SSRIs), the most commonly prescribed class of antidepressants in the U.S., with birth defects, including heart wall defects and misshapen skulls.

But a new, large study involving almost 30,000 women by U.S. and Canadian researchers found that SSRIs were mostly safe to the growing fetus.

The findings, examining data taken from the U.S. National Birth Defects Prevention Study, were published in the British Medical Journal.

“Reassuringly, we found that we could not replicate five earlier reported links with birth defects for sertraline, which is the most commonly used SSRI in our U.S. study population," said Jennita Reefhuis, a birth defects epidemiologist at the U.S. Centers for Disease Control and Prevention in Atlanta, Georgia, and lead author of the investigation. "We did repeat some links reported before for paroxetine and fluoxetine. But it is important to keep in mind that even for these confirmed links, the risk for an individual woman who is taking [these medications] is still relatively small.”

Forty percent of expectant mothers who take SSRIs early in their pregnancies are prescribed the safest drug, sertraline, known as Zoloft.

Two other SSRIs, Prozac and Paxil, were found to have very little association with birth defects.

Edward McCabe, chief medical officer of the March of Dimes, an organization that funds research into birth defects, called the study "very good news."

“You know, we always tell women not to go off your medications without talking to your health care provider," McCabe said. "The new information gives reassurance to the health care provider and to the woman suffering from depression that she can treat herself and that it’s safe for her baby.”

The authors of the BMJ study called for continued research into a small but unknown risk of birth defects to reassure women that all SSRIs are safe to use during their pregnancies.