A study by researchers at the University of British Columbia in Vancouver has uncovered a higher risk for low birth weight and respiratory distress in infants born to mothers on SSRI antidepressants.

SSRIs, or selective serotonin reuptake inhibitors, work by preventing the reuptake, or re-absorption, or serotonin in the brain. Serotonin is considered a key ingredient in the chemical mix that affects mood levels. Dr. Tim F. Oberlander and colleagues examined population health data for nearly 120,000 live births between 1998 and 2001, of which 14 percent of children were born to mothers diagnosed with depression.

Researchers compared neonatal outcomes of 1451 children born to mothers diagnosed with depression and treated with SSRI medications to 14,234 children of mothers also diagnosed with depression but not treated with SSRIs. Children whose mothers took SSRIs suffered a 13.9 percent rate of respiratory distress, which is significantly greater than the 7.8 percent experienced by the children of mothers who did not take the drugs. In addition, infants whose mothers were on SSRIs experienced longer hospital stays, lower birth weights, and earlier gestational age. A larger proportion of babies born to mothers on SSRIs were born before 37 weeks.

“Our study may add another cautionary note to the use of SSRI medications during pregnancy,” Dr. Oberlander said, explaining that the study’s findings are contrary to an expectation that treating mothers for their depression would help lessen the adverse neonatal consequences associated with maternal depression, such as poorer cognitive performance, behavioral problems that can extend into adolescence, lower IQ scores, and disorders such as attention deficit/hyperactivity disorder (ADHD).

Sources: David Douglas, “Antidepressants during pregnancy may affect baby,” Reuters Health, August 25, 2006; Canadian Pediatric Society, “Maternal depression and child development,” Pediatrics & Child Health 9 (October 2004).