To Treat or Not to Treat During Pregnancy: That Is the Question

The association of major depressive disorder (MDD) with preterm birth or low birth weight does not appear to be strong; at the same time, antidepressant medication use is a distinct risk factor but the overall effect is not large, reducing duration of gestation by only about 3-5 days. And importantly, other factors, such as adverse health habits, play an important role in confounding these findings.

That was the message Kimberly Yonkers, M.D., brought to a symposium at APA’s 2014 annual meeting. Yonkers is a professor in the departments of psychiatry, obstetrics, gynecology, and reproductive sciences and director of the PMS and Peripartum Psychiatric Research Program at Yale University School of Medicine.

Yonkers said there has been “explosion of information” in recent years about the varying effects of depression and other mental disorders and the use of antidepressants on pregnancy outcome, as more and more women of childbearing age are being treated with antidepressants. However, many of these studies have been plagued by various methodological problems and by the fact that other health factors can affect outcome. Moreover, it is known that women who use antidepressants are more likely to be using other medications as well.

But Yonkers described several studies that are bringing clarity to a fraught subject, as well as evidence of the “biological plausibility” for the effect of mental illness on pregnancy outcome. Among those studies is the NIMH-funded “Pink and Blue” study at Yale, which investigated whether a depressive disorder or antidepressant treatment occurring in pregnancy increases the risk of preterm delivery or delivery of a low birth weight or small-for-gestational-age neonate.

In that study women were recruited by 16 weeks gestation or earlier from 36 obstetrical practices and hospital-based clinics and had a depressive disorder or posttraumatic stress disorder in last five years or were undergoing antidepressant treatment in pregnancy. They were compared with unexposed controls.

Generally, antidepressant use was associated with preterm birth, particularly spontaneous preterm birth, but it increased the risk by less than 50 percent. In contrast, use of cocaine increased risk of preterm delivery 5.5 fold (550% increase); use of opiates increased risk of preterm delivery by nearly threefold (286% increase); and smoking two or more cigarettes increased the risk of “small-for-gestational age” by nearly fourfold (374% increase).

“The effect of antidepressants and depression is minor compared with other common exposures,” Yonkers said. “We need to do more to stem exposures of hazardous substances like cocaine, opiates, and nicotine`.”