Expectant moms who suffer from depression are at greater risk for having an early delivery, according to a new study published in the American Journal of Obstetrics & Gynecology.
The researchers found that of more than 14,000 pregnant women, those who were identified for possible clinical depression had an increased chance of preterm birth: 14 percent delivered before the 37th week of pregnancy compared to 10 percent of non-depressed women.
After the researchers accounted for other factors, such as the mother’s race and age, depression was still linked to preterm birth risk. However, there were other variables that the study could not factor in, such as the mother’s smoking and drinking habits during pregnancy, and pre-pregnancy weight. So there could be other explanations.
Although the findings do not prove that the connection is cause and effect, the results are similar to past studies that found a link between prenatal depression and preterm birth, said senior researcher Dr. Richard K. Silver, of the NorthShore University HealthSystem and University of Chicago in Illinois.
And since depression is a type of serious stress for moms, a link to preterm birth is also “biologically plausible,” said Silver.
Other studies have shown that moms who take antidepressants during pregnancy have a higher risk of preterm birth — though that does not prove that medications are the culprit.
The current study’s results are based on more than 14,000 women who were screened for prenatal depression between 2003 and 2011. Nine percent came up positive for being at risk for clinical depression and were referred for a full evaluation. Overall, those women were 30 percent more likely than symptom-free women to deliver early.
Silver said he’s not aware of research suggesting that depression treatment—whether it’s medication or talk therapy—improves the timing of delivery. “That’s to be determined,” Silver said.
It’s a difficult topic to study, he noted, since researchers cannot ethically conduct a clinical trial in which they withhold treatment from some depressed pregnant women while treating others.
So researchers must rely on studies that, for example, look back at women’s medical records and see if those who were treated for depression delivered earlier than those whose depression went untreated. And still, those types of studies are difficult to determine if the results are cause-and-effect.
As for depression treatment, many expectant mothers do not want to take medication of any kind, Silver noted. Talk therapy or support groups are also options, he said—though the availability can be limited, and insurance coverage spotty.
Currently, doctors vary in whether they screen pregnant moms for depression. Silver said his guess is that fewer than half of pregnant women in the U.S. are screened.