Listeria in pregnancy and foods to avoid
Posted on 7 February 2017
To avoid a possible listeria infection, pregnant women are advised to avoid some foods where possible and take precautions to cook certain foods thoroughly.
As soon as a woman finds out she’s pregnant, eager friends and family start offering advice about what she should and shouldn’t eat and drink. But there’s more to a pregnancy diet than just avoiding unhealthy foods that don’t offer benefits to the rapidly growing baby. Listeriosis is a rare but devastating bacterial infection that in pregnancy can lead to stillbirth.
Listeria in pregnancy
Listeria is a bacteria that lives on some animal products, and if ingested it can cause a mild infection called listeriosis. However, a listeria infection during pregnancy carries the risk of being passed to the baby and can cause a miscarriage or stillbirth.
Fortunately, listeriosis in pregnant women is rare in South Africa, says Dr Elizabeth De Gouveia, a gynaecologist & obstetrician at Mediclinic Gynaecological Hospital in Sunnyside. However, she adds, pregnant women are still advised to avoid certain foods where possible or take precautions to cook food thoroughly.
Foods to avoid in pregnancy
Dr De Gouveia recommends avoiding any raw animal or fish product. ‘Meat must be well cooked, eggs yolks should be set, milk products should be made from pasteurised milk, and raw fish should be flash-frozen,’ she says.
Other foods that could cause listeriosis because of the time they spend on-shelf include:
- soft and semi-soft cheeses
- cold meats
- cold cooked chicken
- pre-prepared vegetables and salads
- pre-cut fruit
- soft-serve ice cream
However, when soft cheeses or cold meats are heated thoroughly, it kills the bacteria that can cause listeriosis.
Testing for listeria in pregnancy
Dr De Gouveia explains that if a mother suspects a listeria infection or a stillbirth occurs, she has the option to test for common causes. Some of the causes for stillbirths that are more common than listeriosis in pregnancy include:
- Toxoplasmosis: a common parasite that causes blurred vision, confusion and loss of coordination
- Cytomegalovirus: a common and normally mild viral infection
- Parvovirus: a common viral infection, especially among children, that causes a facial rash
If listeriosis is suspected, a diagnosis can be made from amniocentesis and DNA isolation of the organism in the amniotic fluid, or from a swab taken at delivery.