Foods and Harmful Substances That Should Not Be Consumed During Pregnancy

High-Mercury Fish

Mercury is a highly toxic element with no safe intake levels.

Excessive consumption may be toxic to the nervous system, immune system, and kidneys. Even low intakes may cause significant developmental problems in children.

Fish that should not be consumed during pregnancy due to their high mercury content include the following:

  • Tuna (especially bigeye tuna)
  • Swordfish
  • King mackerel
  • Shark

It is important to note that not all fish contain high levels of mercury; only certain species do.

Low-mercury fish is very healthy to consume during pregnancy and can be consumed three times a week.

Anchovies, haddock, salmon, and trout (freshwater) are fish with low mercury content.

Oily fish, such as salmon and anchovies, are particularly good choices, as they are rich in omega-3 fatty acids, which are essential for your baby.

Undercooked or Raw Fish

Raw fish, especially shellfish, may lead to various infections. These may be viral, bacterial, or parasitic infections caused by several agents such as norovirus, VibrioSalmonella, and Listeria.

Some of these infections may only affect you, causing dehydration and fatigue. Other infections may be passed on to your baby, leading to serious consequences.

Pregnant women, particularly, are not resistant to Listeria infections. This bacterium may be found in soil, contaminated water, or plants.

Even if you do not show any signs of illness, the bacteria, Listeria, may pass through the placenta to your baby and cause significant health problems.

It is recommended that you avoid raw fish and shellfish during pregnancy.

Undercooked – Raw & Processed Meat

Eating undercooked or raw meat increases your risk of developing bacterial or parasitic infections due to the following agents, including ToxoplasmaE. coliListeria, and Salmonella.

Bacteria may threaten your baby’s well-being and cause severe neurological problems.

Raw Egg

Eating raw eggs carries the risk of exposure to Salmonella.

Symptoms of Salmonella infections include fever, nausea, vomiting, stomach cramps, and diarrhea.

Products such as soft scrambled eggs, homemade mayonnaise, some homemade salad dressings, homemade ice cream, and homemade cake creams often contain raw eggs.

Make sure you always fully cook the eggs.

Unwashed Products

The surfaces of unwashed or unpeeled fruits and vegetables may be contaminated with various bacteria or parasites.

Contamination may occur at any time during production, storage, and transportation.

During pregnancy, it is critical to wash, peel, or cook fruits and vegetables thoroughly to reduce the risk of infection.

Unpasteurized Milk – Cheese and Fruit Juice

Raw milk and unpasteurized cheese may contain many harmful bacteria. The same bacterial contamination applies to unpasteurized fruit juice.

Pasteurization is the most effective method for killing all harmful bacteria while retaining the nutritional value of the products. All bacterial infections may lead to severe problems for an unborn baby.

Consume only pasteurized milk, cheese, and fruit juices to minimize the risk of infection.


Expectant mothers should limit their caffeine intake to less than 200 mg per day. Caffeine is readily absorbed from the gastrointestinal system and easily crosses the placenta. Caffeine accumulation in the fetus may develop because the fetus cannot metabolize caffeine. High caffeine intake during pregnancy has been demonstrated to be associated with fetal growth retardation and an increased risk of low birth weight. Therefore, do not consume more than one cup of coffee per day to make sure your baby is not exposed to too much caffeine.


You should avoid consuming alcohol while pregnant. Even a trace amount may interfere with your baby’s brain development.

You should abstain from alcohol throughout pregnancy because no safe levels of alcohol have been established.


During pregnancy, the effects of smoking on the fetus are associated with the chemicals in cigarette smoke. Major components include nicotine, carbon monoxide, and cadmium.

Smoking during pregnancy may lead to many serious problems, such as:

  • Premature birth
  • Delayed growth
  • Low birth weight
  • High blood pressure during infancy and childhood

Smoking and alcohol use should be stopped before pregnancy.


During pregnancy, medications should be used under the close supervision of a physician.


  1. Bjarnadottir, A. (2020). 11 Foods and beverages to avoid during pregnancy – What not to eat. Healthline.
  2. Özalper, B. (2014). Gebelikte beslenme. Muş Alparslan Üniversitesi Fen Bilimleri Dergisi2(2), 270-278.