When it comes to understanding the potential risks of antidepressants such as Effexor and Effexor XR, large studies are the most important. Many initial drug safety studies only include a few hundred participants, which can in some cases be dismissed or belittled as statistically insignificant. However, a recent Canadian study involving 5,000 expectant mothers will be significantly harder to ignore on these grounds. This study found that Effexor might have a link to one of the most common and devastating birth conditions — the miscarriage.

The 5,000 women were a section of a larger group of nearly 70,000 pregnant women, and were those out of the group who had suffered a miscarriage. The study looked at the women who had unfortunately suffered this condition, and analyzed trends that may have affected their pregnancies. Specifically, the study found that women who were on antidepressants had an approximately 68 percent increase in likelihood of having a miscarriage versus those who were not. Effexor and Paxil were specifically named as antidepressants that came up in the study.

Doctors involved in the study had several comments to make about the matter. The first was to caution people against jumping immediately to conclusions; the study does not prove or conclusively state that antidepressants cause miscarriage. For example, it might be that depression itself is the cause, and depressed women are more likely to take antidepressants. However, the study did not rule a causal relationship out, either. They elaborated that even if such a link was not conclusively established, it did raise certain questions about the methods of treating female patients for depression when they were likely to become pregnant.

One potential explanation is that antidepressants cause an excess of pressure on the uterus during the pregnancy, leading to a spontaneous miscarriage. Further study will be necessary before this hypothesis can be affirmed, but it is an attempt to start the process of understanding this frustrating situation.