Asian pregnant woman holding out hands to reject a hamburger on a plate.

What nutrients should a pregnant woman avoid?

You’re pregnant, or maybe thinking of getting pregnant, and as soon as the cat’s out of the bag, you’re a walking target for opinions, advice, and everything in between. 

You might have heard any number of these phrases about prenatal nutrition – Don’t eat cheese. – No more coffee. – No more seafood.

Prenatal nutrition is key to reducing risks during pregnancy and birth. Before making radical changes in your diet, please consult with your ObGyn. Moreover, working with a pregnancy dietitian nutritionist can help ensure you receive the nutrients you need and guide you on the foods that you should restrict or avoid.

There are guidelines about which nutrients and foods a pregnant woman should avoid and why

Avoid seafood high in mercury. Seafood is an excellent source of protein and Omega-3 fatty acids to promote your baby’s brain and eye development. That said, some seafood is high in mercury which can hurt your baby’s developing nervous system. So, which seafood (and fish) are safe?

  • Anchovies
  • Catfish
  • Cod
  • Herring
  • Light canned tuna
  • Pacific oysters
  • Pollock
  • Salmon
  • Sardines
  • Shad
  • Shrimp
  • Tilapia
  • Trout

Beware of how seafood is prepared. Seafood contains a lot of bacteria which can cause harm to both mom and her developing baby. Avoid all raw fish and raw shellfish (sushi, sashimi, ceviche). Avoid undercooked and refrigerated seafood (nova style, lox, kippered, smoked, jerky). 

Now is not the time to go rare. Undercooked meats also carry bacterias that can cause harm to the mom, who is more at risk of bacterial food poisoning. Make sure all meats (chicken, fish, beef, pork) are fully cooked. Likewise, cook eggs until the yolks are firm. 

Put unpasteurized foods on hold. Like undercooked meats, unpasteurized foods can lead to foodborne illnesses. Soft cheeses like brie, blue cheese, and feta are often unpasteurized and should not be consumed unless they are labeled otherwise. (Goodbye wedge salad!) Same for any milk products prepared with unpasteurized milk (salad dressings, desserts etc.)

Reduce Caffeine intake: This doesn’t mean you have to stop drinking coffee altogether. It’s proven that caffeine does penetrate the placenta, though its effects are unclear. Doctors recommend limiting caffeine to less than 200 mg/day. What does that look like? An 8-ounce cup of brewed coffee contains about 95 mg of caffeine. An 8-ounce cup of brewed tea has about 47 mg of caffeine. And a 12-ounce can of caffeinated soda has about 33 mg of caffeine.

Avoid unwashed fruits and vegetables. This goes for everyday life as well, but since pregnant women are more at risk for foodborne illnesses, wash your fruits and vegetables well!

Beware of herbal.”Herbal” and “all natural” labels aren’t regulated, and herbal tea, pills, vitamins etc. haven’t been studied sufficiently to see if they are safe for your developing baby.

Always check with your healthcare provider when you have doubts.

During pregnancy, a woman’s immune system undergoes changes to accommodate the growing fetus. Pregnancy is associated with a state of immune suppression, which means that the body’s immune system is less active than usual. This is believed to be a protective mechanism to prevent the mother’s immune system from attacking the developing fetus, which has foreign genetic material.

The hormonal changes that occur during pregnancy can also affect the immune system. For example, the hormone progesterone can suppress the activity of certain immune cells, including T cells and natural killer cells. As a result of these changes, pregnant women may be more susceptible to certain infections, such as the flu, as well as certain types of bacteria that can cause urinary tract infections.

Good nutrition from before getting pregnant to postpartum diet plans can protect a mother and her developing baby, helping boost her immune system against foodborne illnesses, infections, and viruses. By avoiding these foods, a pregnant woman increases her chances of a healthy pregnancy and labor.