Clinical |

Ob-Gyns Address Management of Listeria During Pregnancy

New Guidelines Respond to Current Public Health Need Following Listeria Warnings

Washington, DC—Responding to recent warnings about risk of listeriosis in the U.S., the American College of Obstetricians and Gynecologists (the College) today released the first medical management guidelines regarding the evaluation and treatment of pregnant women exposed to the bacteria listeria. The Committee Opinion, “Management of Pregnant Women with Presumptive Exposure to Listeria Monocytogenes,” is also the first released through the College’s “publish ahead-of-print” process, in which completed guidelines are expedited in response to a public health need.


The incidence of listeriosis among pregnant women is approximately 13 times higher than in the general population. The foodborne illness can cause significant fetal and perinatal complications, including miscarriage, preterm labor, and stillbirth, as well as neonatal listeriosis and possible neonatal death. Recent recalls of listeria-contaminated food products have highlighted the potential for pregnant women to be exposed to the bacteria.

“Not only are pregnant women especially susceptible to listeriosis infections, but because the infection may spread into and across the placenta, infection also puts their fetus at significant risk,” said Jeffrey L. Ecker, MD, chair of the College’s Committee on Obstetric Practice, which developed the Committee Opinion. “It is essential for ob-gyns not only to be aware of the best ways to manage the care of a pregnant patient who has been exposed to listeria bacteria, but just as important, to counsel pregnant women regarding how to avoid potential exposure.”

The Committee Opinion breaks down the management recommendations for listeria-exposed pregnant women into three groups: asymptomatic, mildly asymptomatic but without fever, and fever with or without symptoms. The Committee Opinion recommends testing for infection and presumptive treatment only for the last group. It notes that although there are limited prospective data supporting treatment plans for pregnant women exposed to listeria, the recommendations reflect case reviews as well as extensive clinical experience.

Fever with or without symptoms: A presumptively exposed pregnant woman with a fever exceeding 100.6º F should be tested with blood cultures. However, because results will not be available for several days, the Committee Opinion recommends that these women should simultaneously be treated for listeriosis and suggests initiating fetal surveillance.

No fever, but with mild symptoms: A pregnant woman who has been exposed to a listeria-contaminated product and is displaying mild symptoms, but does not have a fever, does not require culture testing, although it may be done. If her blood is tested, the laboratory should be informed about the potential threat of listeriosis, to prevent the bacteria from being mistaken for a contaminant with a similar appearance.

No symptoms: For asymptomatic women, no testing is called for, though women should be tested if symptoms develop within two months of exposure. In this case, listeriosis-related fetal surveillance is not necessary.

“As an obstetrician, I have heard from patients who have been concerned that they may have been exposed to listeria,” said Dr. Ecker. “These recommendations will help to inform the care that we give to our patients, and will help us to alleviate their concerns about their health and their babies’ health. Fortunately most women who are exposed won’t develop a listeria infection, and in many cases, careful observation for fever or other signs and symptoms is all that is needed.”

Symptoms of listeriosis may be similar to a flu-like illness and can include fever, muscle pain, backache, headache, and gastrointestinal symptoms, including diarrhea.

The Committee Opinion also reminds pregnant women not to eat foods with a high risk of listeria contamination. These include:

  • hot dogs, lunch meats, or cold cuts served cold or heated to less than 165 degrees;
  • refrigerated pâté and meat spreads;
  • refrigerated smoked seafood;
  • raw (unpasteurized) milk;
  • unpasteurized soft cheeses, such as feta, queso blanco, Brie, and blue-veined cheeses; and
  • unwashed raw produce (when eating raw fruits and vegetables, skin should be washed thoroughly in running tap water, even if it will be peeled or cut).

The American College of Obstetricians and Gynecologists (The College), a 501(c)(3) organization, is the nation’s leading group of physicians providing health care for women. As a private, voluntary, nonprofit membership organization of approximately 58,000 members, The College strongly advocates for quality health care for women, maintains the highest standards of clinical practice and continuing education of its members, promotes patient education, and increases awareness among its members and the public of the changing issues facing women’s health care. The American Congress of Obstetricians and Gynecologists (ACOG), a 501(c)(6) organization, is its companion organization.