Listeria and Pregnancy: Foods to Avoid and Why

A glass of fresh lben at your mother-in-law’s, a piece of jben bought at the souk, a plate of cold cuts at a wedding. During pregnancy, these everyday pleasures raise a question: could they pass on listeriosis? This food-borne infection is rare, but it is one of the few that can reach the baby directly.

The good news is that the bacterium responsible, Listeria monocytogenes, is destroyed by cooking, and a few habits are enough to protect yourself. Here is why doctors worry about it, which foods to avoid in Morocco, how to organise your fridge and when to seek care.

Why is listeriosis dangerous in pregnancy?

Because pregnancy makes you more vulnerable and the bacterium can cross the placenta. According to the World Health Organization (WHO), the risk of catching listeriosis is about 20 times higher in a pregnant woman than in a healthy adult.

In the mother-to-be, the infection often goes unnoticed or looks like mild flu. In the baby, it can be serious: miscarriage, stillbirth, premature birth, or infection of the newborn with breathing difficulties, meningitis or sepsis, as described by the French Association of Ambulatory Paediatrics. In France, where the disease is monitored, there are 300 to 400 cases a year, about 5 per 100,000 births, and stillbirth occurs in 25 to 30% of pregnancy-related forms, according to Santé.fr.

In Morocco, we found no published figures on human cases. The bacterium itself is around: a study in Meknes found it in 7% of the raw beef samples analysed (10 out of 140), published in 2020 in the journal Germs. One more reason to cook meat thoroughly.

Why isn’t the fridge enough?

Because Listeria likes the cold. Unlike most germs, it survives and keeps multiplying at fridge temperatures, up to about 5 °C, the WHO explains. A contaminated food does not change smell or appearance: you cannot spot it by eye.

What destroys it is heat. A risky food cooked or reheated until it is scalding hot and steaming right through becomes safe. All prevention rests on two ideas: avoid ready-to-eat foods that keep for a long time in the cold, and cook or reheat thoroughly.

Which foods should you avoid in pregnancy in Morocco?

French and British health authorities and the WHO point to the same families of food. Adapted to our tables, they look like this:

On hard cheeses, countries differ: the NHS considers them safe even when made with raw milk, whereas French sources advise avoiding all raw-milk cheese and cutting off the rind of the others. Choosing pasteurised cheeses settles the question.

The rest of the pregnancy plate, including fish to limit, caffeine and herbal teas, is covered in our article on eating during pregnancy. For raw meat, raw vegetables and cats, the precautions against the other big food-borne infection of pregnancy are gathered in our article on toxoplasmosis.

Fridge and kitchen: habits that protect you

Morocco’s heat makes these habits even more useful, especially in summer and on chergui days (the hot, dry wind).

1. Set the fridge to 4 °C at most, as the French Association of Ambulatory Paediatrics recommends, and check it with a fridge thermometer. The NHS sets the limit at 5 °C.
2. Clean it often, then disinfect it with diluted bleach, rinsing well.
3. Keep raw and cooked apart: raw meat at the bottom, in a closed container, cooked dishes and ready-to-eat products above. Airtight storage boxes prevent leaks.
4. Respect use-by dates, and finish opened products within 2 days unless the packaging says otherwise, advises the NHS.
5. Don’t leave ready-to-eat foods lying around: the NHS recommends eating them within 4 hours of taking them out of the fridge.
6. Reheat leftovers until scalding hot right through, and eat them straight away.
7. Wash fruit, vegetables and herbs, and wash your hands and utensils after handling raw meat.

Ramadan multiplies leftovers and dishes prepared in advance: our article on Ramadan during pregnancy helps you plan, whether you fast or not.

What are the symptoms of listeriosis?

They are often mild, and that is what makes it a trap. In pregnant women, Santé.fr mainly describes fever, headaches and muscle aches, like flu. The NHS adds chills, nausea or vomiting, diarrhoea, tummy pain, and sometimes a baby who moves less than usual. Many women have no symptoms at all.

Symptoms can also appear a long time after the meal responsible. For pregnancy-related forms, Santé publique France reports a median delay of 27.5 days, ranging from 17 to 67 days. The WHO mentions up to 90 days for invasive forms. So there is no point hunting for the culprit in last night’s dinner: simply tell the doctor what risky foods you may have eaten in the previous weeks.

If you have a fever of 38 °C or more, take it seriously, even if you feel more or less well. And if your baby moves less, do not wait: our guide to your baby’s movements during pregnancy explains what to watch for.

How is it treated?

With antibiotics, and the earlier they are started, the better. The doctor orders blood cultures, blood tests that look for the bacterium, and a urine test. Treatment relies on an antibiotic from the penicillin family, prescribed for two to three weeks in pregnant women, according to Santé.fr. In some cases, the team decides to deliver the baby early so they can be treated directly: the warning signs before term are explained in our article on threatened premature labour.