Some SSRIs (but not others) associated with birth defects

Pregnant!The association between maternal use of antidepressants, especially selective serotonin reuptake inhibitors (SSRIs) during pregnancy, and birth defects in newborns and infants, has been the topic of much discussion in recent years. A new study, published in the BMJ, finds a small increased risk of two SSRIs (Paxil/paroxetine and Prozac/fluoxetine) with some birth defects, but not others (including the most commonly used SSRI, Zoloft/sertraline).

For the study, lead author Jennita Reefhuis, PhD, of the CDC, and colleagues analyzed data from the US National Birth Defects Prevention Study, which included almost 18,000 mothers of infants with birth defects and almost 10,000 mothers of infants without birth defects, born between 1997 and 2009. Use of SSRI drugs, which included citalopram (Celexa), escitalopram (Lexapro), sertraline (Zoloft), fluoxetine (Prozac), and paroxetine (Paxil) during the period of time from one month before conception through the third month of pregnancy was recorded over 1200 women reported such use.

The researchers found that both Prozac and Paxil were linked to increased risks of certain birth defects. Prozac was associated with increased risks of heart wall defects and craniosynostosis (misshapen skull). Paxil was associated with increased risks of heart defects, anencephaly (the absence of a major portion of the brain or skull), and abdominal wall defects.

Previous studies have linked Zoloft to some birth defects. However, in this study, Zoloft was not found to be associated with birth defects. This is good news about 40 percent of women using an SSRI during early pregnancy use Zoloft.

The authors caution that their study did have limitations. For example, there was a lack of data on the dose of SSRIs taken by the women and the reasons why women were prescribed the drugs. And like all observational studies, it cannot be confirmed whether the birth defects was caused by the SSRI treatment, maternal disease, or some other factor. The authors also note that the data used were self-reported based on interviews.

Although our analysis strongly supports the validity of the associations that were observed, the increase in the absolute risks, if the associations are causal, is small, the authors concluded.

Dr. Gil Ross, senior director of medicine and public health at The American Council on Science and Health, had this comment: First of all, women being treated for clinical depression with an SSRI should not stop taking their medication based upon this study or any study without discussing their concerns with their doctor. An exacerbation of depression due to inadequate treatment is a major risk factor for adverse events for both mom-to-be and new baby. Next, the increased risk associated with two of these drugs was quite small, so even if causal in fact, the effect is likely to be very uncommon. Some celebrity spokesmen, notably the scientologist Tom Cruise, has publicly denounced the use of anti-depression medicine: he should be ignored or told to stick to his own business and leave medical care to doctors and their patients.