The results, reported May 25 online in the journal Epidemiology, are good news for women who worry that their depression will harm their baby. Researchers also stress that women who take antidepressants during pregnancy should not be overly alarmed.
“Women did not ask to be depressed and yet they worry that their depression may affect their baby,” said Kimberly Yonkers, professor of psychiatry and of obstetrics, gynecology, and reproductive sciences. “This study tells them they should not worry that they are somehow compromising their pregnancy because they are depressed. And when considering whether to take medication for depression, women should understand that the risk of preterm birth is only one of many factors they should weigh.”
The study found that taking serotonin reuptake inhibitors (SRIs) during pregnancy significantly increased risk of what is called a late preterm birth. Late preterm birth is defined as at least 34 weeks after gestation but before 37 weeks. Antidepressant use is not associated with early preterm birth, which is much more dangerous to the baby.
Yonkers said that several previous studies suggested depression itself might lead to premature birth. The Yale team studied almost 3,000 pregnant women, including those who were diagnosed as depressed during their pregnancy. After controlling for numerous variables such as health history, age, drug use, and socio-economic status, they found no association between depression and premature birth.
They did find a significant risk of preterm birth among women who were taking anti-depressants. So should depressed women not take antidepressants?
“A woman should always consult with her doctor, but if she is symptomatic and suffering the use of antidepressants may be indicated,” Yonkers said.
Kathleen Belanger of Yale was senior author of the paper. Megan V. Smith, Nathan Gotman and Haiqun Lin are other Yale-affiliated authors.
The research was funded by grants from the National Institute of Child Health and Human Development of the National Institutes of Health.