What are the signs of listeria infection in pregnancy?

What the evidence says

Listeria is a germ found in some foods that can make pregnant people sick. The good news is that most people who are infected only get mild symptoms, similar to a flu. These can include fever, chills, muscle aches, headache, and sometimes diarrhea or an upset stomach.

What makes this infection tricky is timing. Symptoms can show up anywhere from a few hours to about 10 weeks after eating the contaminated food. This long delay means you might not connect a fever weeks later to something you ate.

Some pregnant people have no symptoms at all, yet the infection can still cross the placenta and harm the baby. This is why any fever during pregnancy, especially after eating a recalled food or a high-risk item like unpasteurized cheese, deli meat, or smoked seafood, should be reported to your doctor or midwife right away.

In rare, more serious cases, the infection can spread and cause a stiff neck, severe headache, confusion, sensitivity to light, or loss of balance. These are signs the infection may have reached the nervous system and need urgent care.

If you think you may have eaten something contaminated, tell your healthcare provider even if you feel fine, and definitely call if you develop a fever. Blood tests can check for the infection, and antibiotics used early can protect both you and your baby.