Antidepressants Linked to Premature Birth
SSRIs Increase Risk; Depressed Women Should Weigh Options
Dec. 3, 2002 -- Using the most widely prescribed type of antidepressant medication during pregnancy may increase the risk of premature delivery, suggests a new study. But the risk is still low, and the drugs don't seem to cause birth defects.
In reviewing records of 432 births over two years, researchers for a Seattle-based healthcare provider noted that several women treated with the popular selective serotonin reuptake inhibitors (SSRIs) anytime during pregnancy delivered babies early, before 36 weeks. The babies also had lower birth weights than babies of women who had depression but were not being treated with SSRIs.
SSRIs include Prozac, Zoloft, and Paxil, which together account for more than $3 billion in annual prescription sales in the U.S.
"I think our finding suggests that women have to weigh the risks and benefits of using SSRIs during pregnancy based on their personal situation," says psychiatrist Greg Simon, MD, MPH, an investigator at Group Health Cooperative's Center for Health Studies and author of the study. "A one-week difference in delivery between 40 and 39 weeks is not significant, but that difference between 35 and 34 weeks starts to matter."
Interestingly, pregnant women treated with another type of antidepressant -- tricyclics -- had no increased risk of premature birth, according to the study, which appears in the December issue of The American Journal of Psychiatry. These older tricyclics, which include Tofranil and Gamanil, are considered to be equally effective in treating depression but are not as widely prescribed because they cause more side effects than SSRIs. They, too, were not associated with any additional risk of birth defects.
"While our study shows there is probably some increased risk in premature delivery from SSRI use, and that's not trivial, it wasn't overwhelming, either," he tells WebMD. "However, it does suggest that premature deliveries are an effect of a specific type of medicine, and not an effect of depression."
Simon says that previous, smaller studies have suggested that SSRI use in pregnancy may increase risk of premature delivery, but how these drugs -- and not other antidepressants -- might increase risk is not fully understood. The study revealed no measurable difference in delivery rates between the three SSRIs, which together have grown in popularity by about 25% annually in recent years.