What Is Listeriosis and How Does It Affect Pregnancy?

Contracting listeriosis during pregnancy can be very dangerous to developing fetuses. Expectant mothers need to take preventative measures regarding their diet.
What Is Listeriosis and How Does It Affect Pregnancy?

Last update: 21 September, 2018

Listeriosis is a dangerous infection caused by a bacteria called Listeria monocytogenes. It especially affects women who are gestating and people with suppressed immune systems.

How does transmission of Listeria monocytogenes occur?

This bacteria is found in a variety of places. These include both fresh and residual waters, domestic animals, vegetation, etc. Direct ingestion of contaminated foods is the main way of contracting Listeria monocytogenes.

In general, when a person presents a listeria infection, doctors automatically blame the consumption of foods contaminated prior to packaging .

The incubation period is long. In fact, up to six weeks can go by before the symptoms of having consumed contaminated food appear. This prolonged lapse of time makes it difficult to determine exactly what food caused the spread of the bacteria.

It’s important to point out that this condition doesn’t occur frequently in those who are in good health. Rather, pregnant women and individuals with suppressed immune systems are more at risk.

Listeriosis during pregnancy

The chances of pregnant women contracting this infection are 20 times higher than those of a healthy adult. Experts estimate that one third of cases of listeriosis occur in pregnant women. If women contract this bacteria during pregnancy, this puts their baby at high risk, as it can cause fetal death.

The hormonal changes that occur during gestation have an effect on pregnant women’s immune systems. As a result, they become more susceptible to listeriosis.

What Is Listeriosis and How Does It Affect Pregnancy?

The best way to reduce the risk of infection during pregnancy is to avoid consuming certain foods. Some foods are more prone to contain listeria monocytogenes, so pregnant women should abstain from them.

The transmission of this infection to the fetus occurs via the placenta. It can occur even when the mother herself has shown no signs of having contracted the infection. The consequences of listeriosis in unborn babies range from neurological damage to premature birth, miscarriage and stillbirth.

Depending on what point in pregnancy a woman contracts listeriosis, the consequences that it causes in the fetus can vary If infection occurs during the first trimester, the chances of not reaching full term are higher.

If infection occurs during the last trimester of pregnancy, then there is a possibility of stillbirth. If the baby is born alive, he or she may have serious health problems.

Newborns that overcome the difficult complications of listeriosis during gestation may still present a severe infection called sepsisIf sepsis reaches a baby’s nervous system, the possibilities of the child developing encephalitis or meningitis increase.

The mortality rate of babies infected with listeria is unfortunately very high.

Advice for avoiding listeriosis during pregnancy

Given that pregnant women are prime candidates for contracting listeriosis, all expectant mothers should follow certain guidelines to avoid this dangerous infection.

Healthy and careful eating during pregnancy

The number one way that this infection spreads is through contaminated foods – mostly processed foods and lunch meats. It’s best to avoid these foods during pregnancy to greatly reduce risks.

To be safe, we recommend discussing your diet with your OB/GYNNo two pregnancies are alike. Some women need to consume more of certain foods than other women. It’s best to get professional and personalized advice from a trusted medical specialist.

“The chances of pregnant women contracting this infection are 20 times higher than those of a healthy adult”

Regular cleaning of your refrigerator

To avoid listeria, we also recommend maintaining a clean refrigerator and keeping close control of its temperature. Your refrigerator’s temperature should always remain below 40°F.

What Is Listeriosis and How Does It Affect Pregnancy?

Strict hand hygiene

Pregnant women need to establish strict habits when it comes to hygiene. This includes washing their hands with antibacterial soap and hot water after handling fresh goods. In the same way, it’s important to carefully and frequently wash all cooking utensils.

Handle raw and cooked foods separately

Avoid handling raw foods and cooked foods at the same time. It’s also important to pay special attention to the washing of fruits and vegetables before eating them. Cook all foods completely before eating them – especially red meats, white meats, fish and seafood. Pregnant women should never eat rare or uncooked meats.

Reduce your consumption of lunch meats and meat derivatives as much as possible. At the same time, you should also minimize your intake of soft-ripened and blue vein cheeses, such as feta and roquefort. It’s better to choose hard cheese and yogurt.

If you want to reheat food, make sure to heat it until it steams. High temperatures contribute to the elimination of bacterias in leftover foods

These measures will greatly reduce your chances of suffering listeriosis. Of course, it’s impossible to say you’re 100% safe, but prevention is always the best medicine against any complication. As for pregnant women, this rule of thumb is more important than ever.


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This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.