By Kate, Tommy's midwifery manager
It’s well known that fish is good for you, and you should aim to eat at least two portions a week in pregnancy as part of a healthy balanced diet, including one portion of oily fish, such as fresh tuna, mackerel or sardines.
Eating fish could help with depression
With depression and mental health problems, such as anxiety, affecting 10-15% of all pregnant women, it’s so important to look after your mental health in pregnancy. So it’s exciting news that a study has found eating a lot of fish (which is already a great source of nutrition in pregnancy) may help protect against depression.
One potential reason given by the researchers was that fatty acids found in fish may be important in various aspects of brain activity. Mind, the mental health charity, have said the study supported other work showing links between diet and mood.
Find out more about the study
Iodine found in fish is good for babies’ intelligence
A study in The Lancet concluded that if all pregnant women took a daily dose of iodine, it could boost children's IQs and lead to health improvements.
Iodine is important for healthy brain development and there is some evidence that the UK population may not be getting enough. While the study recommended pregnant women take a supplement of iodine, Public Health England (PHE) said a varied diet should offer enough iodine. The main source in the UK diet is milk but it can also be found in other types of dairy, fish and - in smaller amounts - some foods made from plants, such as cereals.
Always speak to your GP or midwife before taking additional supplements in pregnancy.
Find out more about the study
How to include fish as part of a healthy balanced diet in pregnancy
Don’t head straight to the chippie this evening for a battered cod and chips (unless it’s an occasional treat!). Get your portion of fish in by trying our recipes for delicious and healthy fish dinners and easy lunches.
Which fish should you avoid or limit?
While all this is great news, there are some types of fish you should avoid and some you should limit in pregnancy.
- Avoid shark, swordfish and marlin as they have high levels of mercury, which could affect your baby’s nervous system.
- Limit tuna to no more than two fresh steaks or four medium cans of tinned tuna a week because it also has high levels of mercury.
- Limit oily fish (salmon, mackerel, sardines, trout, herring, pilchards) to no more than two portions a week as they contain pollutants.
- Avoid eating raw shellfish, such as oysters, as they may give you food poisoning. (Cooked shellfish are fine – these include cold pre-cooked prawns.)
Find out more about foods to avoid during pregnancy.
Including
fish in your diet is a good way to get protein and healthy omega-3 fatty acids without ingesting too many saturated fats. However, nearly all fish contain some traces of mercury.
In 2017, the U.S. Food and Drug Administration (FDA) and the U.S. Environmental Protection Agency (EPA) issued revised advice regarding fish consumption for pregnant women or women who may become pregnant, as well as breastfeeding mothers and parents of young children.
Official recommendations
The American College of Obstetricians and Gynecologists (ACOG) encourages pregnant women, women who may become pregnant, and breastfeeding mothers to follow the FDA and EPA's revised advice (see chart):
Eat 2-3 servings a week (8 to 12 ounces in total) of a variety of fish
Eat only 1 serving a week (no more than 6 ounces) of some fish, such as albacore (white) tuna and fish with similar mercury concentrations to albacore (white) tuna
Avoid certain fish with the highest mercury concentrations
Check for advisories for fish caught by family and friends and where no advisories exist; limit eating those fish to one serving a week and do not eat other fish that week.
Women who follow this advice may experience the benefits of seafood consumption without experiencing an increase in related risk from mercury to themselves or their babies.
About mercury
Mercury is a metal that occurs naturally in the environment and that is increased by industrial pollution. Most people are not affected by these tiny amounts of mercury. If a woman is exposed to high levels of mercury before or while she is pregnant, her health and the baby's health are threatened. Babies exposed to mercury in the womb can suffer:
Severe nervous system damage
Brain damage
Learning disabilities
Hearing loss
Have questions?
Discuss these recommendations and the potential benefits of seafood consumption with your obstetrician-gynecologists or other obstetric providers. In addition, your regional Pediatric Environmental Health Specialty Unit (PEHSU) have staff who can also talk with parents about concerns over environmental toxins.
Keep in mind the 3 serving/12 ounces per week limit to avoid the harmful effects of mercury.
More information
Things to Avoid When Breastfeeding
Protecting Your Children from Contaminated Fish
Update on Seafood Consumption During Pregnancy (ACOG Practice Advisory)
What You Need to Know About Mercury in Fish and Shellfish (EPA.gov)
Pediatric Environmental Health Specialty Units (PEHSUs)
The information contained on this Web site should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.