Laurie Barclay, MD

March 2, 2010 — Antidepressants may permanently or reversibly affect fetal brain development depending on the timing of exposure during pregnancy, according to the results of a study reported online February 22 in the March issue of Pediatrics.

“In animals, antidepressant exposure in early life causes changes that persist into adulthood,” write Lars Henning Pedersen, MD, PhD, from Aarhus University in Aarhus, Denmark, and colleagues. “Results from human studies have been equivocal and either found no association between antidepressants and fetal brain development or suggested subtle effects on fine motor development.”

The goal of the study was to evaluate whether there is an association between antidepressant exposure in utero and achievement of developmental milestones at ages 6 and 19 months, using data from the Danish National Birth Cohort. Of the pregnant women in this cohort who were eligible for the study, 415 reported use of antidepressant medication, 489 reported depression without medical treatment, and 81,042 reported neither depression nor use of psychotropic medication.

Compared with children of women not exposed to antidepressants, children with second- or third-trimester exposure to antidepressants were able to sit up 15.9 days later (95% confidence interval [CI], 6.8 – 25.0) and to walk 28.9 days later (95% CI, 15.0 – 42.7). However, these milestones were still within the normal range of development.

Compared with children of women not exposed to antidepressants, fewer children with second- or third-trimester exposure to antidepressants could sit without support at age 6 months (odds ratio [OR], 2.1; 95% CI, 1.23 – 3.60), and fewer could occupy themselves at age 19 months (OR, 2.1; 95% CI, 1.09 – 4.02). There were no statistically significant associations of any of the other milestones measured with in utero antidepressant exposure.

Limitations of this study include possible confounding by the severity of disease, lack of blinding of the participants or the interviewers, and not all women completing the 4 interviews.

“The results of this study suggest a permanent or reversible effect of antidepressant exposure on fetal brain development, which may depend on the timing of exposure during pregnancy,” the study authors write. “We found associations between exposure to antidepressants in late pregnancy and motor development, particularly for boys. The clinical and public health relevance of the results is not known, and longer follow-up monitoring of the children is needed.”

The Lundbeck Foundation funded this study, which also received support from the National Danish Research Foundation, Aarhus University, the Danish Society of Obstetrics and Gynecology, the Ville Heise Foundation, and the Rosalie Petersen Foundation. Drs. Pedersen and Olsen received grants from the Lundbeck Foundation, which is an independent foundation supported by the pharmaceutical company Lundbeck.

Pediatrics. Published online February 22, 2010.

Authors and Disclosures
Laurie Barclay, MD

Freelance writer and reviewer, Medscape, LLC

Disclosure: Laurie Barclay, MD, has disclosed no relevant financial relationships.