Pregnant women have many choices to make when eating for two. What supplements to take, which cheeses to avoid, how much (if any) alcohol is safe to consume, and which fish to avoid – with so many decisions to make just over their food, it’s no wonder pregnant women can experience anxiety.

But a new study – from researchers at the UK’s Bristol University and Brazil’s Federal University of Rio de Janeiro – reveals that pregnant women who eat seafood frequently will likely have lower levels of overall anxiety than those who do not.

The study, which was recently published in PLOS ONE, followed 9,530 pregnant women who kept a food questionnaire documenting their dietary intake over the course of their pregnancy. At 32 weeks, their anxiety symptoms were measured by the team.

Those women who never ate seafood were 53% more likely to have high levels of anxiety, compared with those women who did eat seafood regularly.

In addition, the study shows that pregnant women who ate a vegetarian diet were 25% more likely to have high anxiety than those who ate meat and fish.

Little is known about the relationship between consuming n-3 polyunsaturated fatty acids (PUFA) – found in fish – and excessive anxiety during pregnancy, which is why the study was first conducted.

The authors note that “large cohort studies have associated gestational anxiety with low birth weight and shorter length of gestation.” Plus, higher anxiety during pregnancy has been linked to negative effects on the neurodevelopment of infants, including stress regulation, say the authors.

According to the research team, this study is the first of its kind to show a relationship between dietary patterns and high anxiety levels during pregnancy. In particular, this study is the first to associate low intake of n-3 PUFA and fish to high anxiety symptoms.

Although the study’s findings serve as a recommendation to eat fish while pregnant, there are guidelines pregnant women should follow.

The Food and Drug Administration (FDA) notes that while fish and shellfish are an important component of a health diet, nearly all of them contain traces of mercury, which, in large quantities, can adversely affect a baby’s developing nervous system.

Therefore, the FDA recommends the following three guidelines:

  • Do not eat shark, swordfish, king mackerel or tilefish, as they have high mercury levels
  • Eat up to 12 ounces (about 28 grams) a week of varying fish/shellfish that are lower in mercury, such as: shrimp , canned light tuna , salmon , pollock and catfish
  • Use local knowledge about the safety of fish caught by family or friends in your local area.

Since one of the new findings in the present study was that vegetarians were 25% more likely to experience high anxiety during pregnancy than women who eat meat or fish, the authors recommend incorporating fish into a vegetarian diet if possible.

Study co-author Pauline Emmet told Psych Central : “Some vegetarians are happy to eat fish from time to time and we would encourage this, especially as we are not sure what ingredient in fish is the most effective.”

The authors say their findings show that dietary counseling during pregnancy with a focus on increased n-3 PUFA intake may be a good idea for women with high anxiety. However, they note that clinical trials are first needed to measure the effectiveness of such a program.

For now, pregnant women may be able to put aside some of their concerns about eating fish since it may be good for both mother and baby.

For more information on what to eat during pregnancy, click here.