According to a recent study, there may be a link between a particular flu vaccine and early miscarriage. While researchers can’t say for sure that the vaccine actually causes miscarriages, they found troubling signs of a possible relationship that they are following up on.
The study, paid for by the Centers for Disease Control and Prevention, included 485 women who had a miscarriage in 2010, 2011 and 2012. Researchers compared the women to 485 pregnant women who did not have a miscarriage. They found that the women who had been vaccinated against influenza 28 days before the miscarriage and in the first trimester of pregnancy were more likely to have a miscarriage.
James Donahue of the Marshfield Clinic Research Institute in Wisconsin said, “We didn’t expect to have these results at all. Once we started realizing that the results were unexpected and we were totally surprised by it, we sort of figured this was going to cause a bit of a stir.”
When researchers studied the data even closer, they found that the link only held true for women who had also been vaccinated the previous flu season. The vaccine in question is the H1N1 vaccine, first introduced in 2009.
A research team is now looking at more data involving more women over a longer period of time. Edward Belongia of the Marshfield Clinic Research Institute explained, “So what we have here is a signal. It’s not definitive. It might be wrong. I have no doubt that we will eventually sort this out and understand what’s going on, but that takes time.”
There are many studies that show vaccination in general during pregnancy is safe. Pregnant women are especially vulnerable to the flu. Dr. Amanda Cohn, senior adviser for vaccines at the CDC, worried that the study would deter pregnant women from being vaccinated. “Really, this study highlights how strong our vaccine safety surveillance is,” she said.
It is important to be aware of what is going in your body. Take extra precautions and be safe.