Antidepressant Medications

One of the questions an expecting mother has to ask herself if she suffers from major depression is, “Should I discontinue my antidepressant medications, for fear of their effects on the baby?” Before today, doctors only had the slightest of data on which to base their medical opinion. But a new study out sheds some much needed light on this question.

The study was conducted on 238 women, who were divided into three mutually-exclusive groups: no SSRI antidepressant usage nor depression; SSRI antidepressant use; or a major depression diagnosis but with no SSRI antidepressant usage. Did the babies all have brain damage or lower IQ scores?

Well, the researchers didn’t conduct any long-term followups for this study. What the researchers (Wisner, et al., 2009) did assess was whether the baby had minor physical anomalies, amount of maternal weight gain, infant birth weight, pregnancy duration, and neonatal characteristics.

What did the researchers discover?

Both antidepressant use and depression itself were predictors for a baby being born “preterm,” that is, sometime before the normal 37 week gestational period for babies. Most of these preterm births were in the “late preterm” period (from 34 to 37 weeks), which is not usually considered a major health risk for the baby. This study joins three others that have also found a similar threefold risk of preterm births when a mother is taking an antidepressant.

But there’s hope for expecting mothers who are currently on an antidepressant and want to avoid the possibility of a preterm birth:

[W]e found that partial exposure to either SSRIs or depression did not increase the risk for preterm birth. Similarly, [other research] reported that mothers who discontinued SSRIs before the third trimester (similar to our group with partial exposure) had a preterm birth rate comparable to the rate for comparison subjects, while mothers with third-trimester exposure (82% treated throughout pregnancy) had an increased rate.

In other words, it appears that discontinuing antidepressant medications only for the third trimester may be all that’s needed to help prevent this one possible risk. Obviously, talk to your doctor before doing anything yourself.

What didn’t the researchers find?

[W]e found that gestational exposure to SSRIs or depression (in unmedicated women) was not related to the number of minor physical anomalies in offspring of women with major depressive disorder. This study and two others have not replicated the original report of a higher rate of minor anomalies in infants exposed prenatally to SSRIs. Moreover, no definitively higher risk for two clinical correlates of minor anomalies — major structural malformations and neurodevelopmental abnormalities or psychiatric problems — has been associated with SSRI exposure. However, one investigative team found normal mental but lower psychomotor skills in toddlers exposed prenatally to SSRIs.

There are a few problems with the study. One is that all three groups of women studied did not have similar demographic representation, which may have contributed to a skew of the results. Another is that there were differing characteristics among the study groups, which again may have skewed the results in ways we do not know. Neither flaw is fatal, but does point to the need for more prospective, observational studies of this design.

As the accompanying editorial notes (Parry, 2009), failure to treat depression in an expecting mother may ultimately result in more negative outcomes for both mother and baby than the possibility of a pre-term delivery:

From the evidence available to date, the risks of an untreated maternal depression are far greater than the risks of serious adverse sequelae from antidepressant medication. As now demonstrated in multiple other studies, major depression during pregnancy may impair the neurocognitive and socioemotional development of the child, predict sleep problems in infancy and toddlerhood, alter neuroendocrine function, and increase the risks of mental and medical disorders in the offspring later in life.

Depression during pregnancy is a risk factor for the development of postpartum depression, and women with postpartum depression are at increased risk for recurrent depressive illness, all of which may further impair the healthy development of the child. In their ongoing longitudinal study of the effects of maternal depression on long-term outcomes in offspring, Murray et al. reported on cognitive and socioemotional impairments in children of depressed mothers at 5 years.

More recently, after 13 years of follow-up, these investigators reported that maternal depression was associated with higher rates of affective disorders in adolescent offspring.

Ultimately the decision to continue depression treatment for an expecting mother is a personal choice between her and her doctor. This research doesn’t change that. But it does shed light on the fact that if a mother decides to continue taking antidepressants during her pregnancy, the biggest risk factor is a pre-term delivery. It also appears to be a risk factor that could be mitigated by discontinuing antidepressants during the third trimester, in consultation with her doctor.

References:

Parry, BL. (2009). Assessing Risk and Benefit: To Treat or Not to Treat Major Depression During Pregnancy With Antidepressant Medication. Am J Psychiatry, 166(5), 512 – 514.

Wisner KL, Sit DKY, Hanusa BH, Moses-Kolko EL, Bogen DL, Hunker DF, Perel JM, Jones-Ivy S, Bodnar LM, Singer LT (2009). Major depression and antidepressant treatment: impact on pregnancy and neonatal outcomes. Am J Psychiatry, 166(5), 557 — 566.