Could Listeria's Threat to Pregnant Women Be Scarier Than We Thought?

A recent study suggests that listeria could be even more dangerous for pregnant women than we previously thought. Here's how to minimize your risk.

Listeria and miscarriage villorejo/Shutterstock
You've probably heard that listeria poses a threat to pregnant women. As we've previously reported, the bacterium (which can cause fever, diarrhea and even death) may be more likely to affect pregnant women. But according to new research, we might be underestimating the risk of listeria exposure.

Researchers from the University of Wisconsin-Madison studied the food-borne bacterium and its effect on fetal development. According to their findings, published in mBio, listeria may cause even more miscarriages than we previously believed. 

"For many years, listeria has been associated with adverse outcomes in pregnancy, but particularly at the end of pregnancy," study author Ted Golos said in a release for this study. "What wasn't known with much clarity before this study is that it appears it's a severe risk factor in early pregnancy."

Researchers suggested that listeria may be a silent danger. Since the virus doesn't always cause severe symptoms for the people it infects, moms might be unknowingly exposed to the bacteria before miscarrying, which could explain skewed data surrounding listeria's effects during early pregnancy.

Listeria often appears in things like unpasteurized milk, soft cheese, raw sprouts, melon and deli meats, which is why those are usually on the no-no list for pregnant women. Obviously, exercising caution where these foods are concerned is a great idea. But how worried should you really be about listeria's threat to your pregnancy?

We spoke with Michael Cackovic, MD, a maternal-fetal medicine specialist at the Ohio State University Wexner Center, to gain more insight.

How to Eat Healthy During Pregnancy: How To Avoid Listeria

“This isn’t anything that’s earth-shattering,” Dr. Cackovic told Fit Pregnancy of the study's findings. “Basically what [listeria] does is it colonizes the placenta. Anytime you colonize the placenta with anything, that’s your lifeline between the mom and the baby. I think as long as they’re following pregnancy guidelines, [pregnant women] should be in the clear.”

Dr. Cackovic's advice for pregnant women who are worried about this news? “I just think that basic precautions [are necessary]. You should wash your lettuce, you should avoid anything that’s inadequately cooked," he said. “The most common symptom [of listeria] is fever. Any time you have a fever you should let your doctor know. Any time you’re sick you really should let your doctor know."