Pregnant women who take antidepressants may have a slightly higher risk of delivering babies with rare birth defects. But the risks posed by the drugs are very small, according to two studies and an editorial in the New England Journal of Medicine.
Both studies examined SSRIs, or selective serotonin reuptake inhibitors, a popular class of antidepressants that includes Pfizer’s Zoloft, and Eli Lilly’s Prozac, and GlaxoSmithKline’s Paxil.
“There appear to be risks, but the risks are small, and they’re limited to specific drugs and not to the entire class,” Carol Louik, lead author of one of the studies told the WSJ.
One risk suggested by both studies: Taking Paxil, or the generic version paroxetine, during pregnancy raises the risk of giving birth to a baby with obstructions in the heart’s right ventricle. That risk has been suggested in previous research, and the drug carries a warning about heart defects in fetuses.
The studies looked at a total of about 30,000 infants, the majority of them with birth defects. Interpreting the studies is tricky. They looked back at existing data, rather than randomly assigning pregnant women to receive either drugs or placebos. That means they research can show association between SSRI use and birth defects but cannot definitively prove that the drugs cause the defects. Also, because they looked at multiple types of birth defects and multiple drugs, there is a chance of finding an association that is due to random chance.
“Patients and physicians alike would prefer it if there were clear lines separating ‘risk’ and ‘no risk’ and if all studies gave consistent results pointing in the same direction,” said the editorial that accompanied the studies. “Unfortunately, this is often not the case, and the data to inform potential risks of SSRIs are no exception.”
Source: WSJ, 06-28-07