Fish, Mercury, Omega-3 and Pregnancy

January 20, 2020 , , ,

This article was originally written on January 20, 2020 and fully updated on September 3, 2022.

Omega-3s are important during pregnancy, and pregnant women are recommended to eat fish in order to help them meet their nutrient needs. However, certain fish have a high content of contaminants, such as mercury, and can interfere with the optimal development of the baby. Here is more information on the subject so you can make informed choices!

Sources and importance of omega-3 during pregnancy

Omega-3 fatty acids are considered essential because they must be consumed through food to meet the body’s needs. There are three types of omega-3 fatty acids, alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Omega-3s are particularly important during pregnancy and breastfeeding since they constitute key nutrients to support brain development in the fetus. Studies show that proper consumption of DHA during pregnancy can help reduce the risk of preterm delivery, low birth weight and perinatal death.

DHA and EPA are found in oily fish while ALA is found in certain plant foods. The following table presents the most frequently eaten fish which have a substantive content of DHA. It should be noted that some eggs are enriched in DHA and ALA and can thus provide an interesting amount of omega-3.

Table 1 : Sources of DHA

Type of seafood (cooked portion) DHA Quantity (mg)*
Atlantic salmon (120 g) 1748
Herring (120 g) 1326
Cod (120 g) 1104
Blue Mackerel (120 g) 839
Pink salmon, canned (120 g) 817
Sardines, canned in oil, with bones (106 g) 648
Rainbow trout (120 g) 624
Light tuna, canned (120 g) 235
Halibut (120 g) 186
Scallops (12 medium size) 162
Oysters (6 medium size) 124
Shrimp (various types), 12 medium size 84
Snow crab, canned (120 g) 79

*Values ​​calculated from the Canadian Nutrient File

DHA requirements during pregnancy

Although there is no dietary reference intake (DRI) or adequate intake (AI) established for omega-3s, experts recommend an intake of 300 mg of DHA per day during pregnancy and breastfeeding. Major health organizations recommend that pregnant and breastfeeding women consume at least two servings per week of low-mercury fish as well as a DHA supplement of at least 200 mg per day.

Pages: 1 2


Kathryn Adel
Kathryn holds a Bachelor Degree in Nutrition as well as a Bachelor and a Master Degree in Kinesiology, all from Laval University. She is a Registered Dietitian and active member of the Ordre professionnel des Diététistes Nutritionnistes du Québec (ODNQ) and of the American Academy of Nutrition and Dietetics. She holds the Monash University's certification for the FODMAP diet and IBS, and has considerable clinical experience in that area. She is also an accomplished athlete, having ran track and cross-country at a national level. Kathryn specializes in sports nutrition, weight loss, diabetes, as well as heart and gastrointestinal health.

Leave a Reply

Your email address will not be published. Required fields are marked *

This website uses cookies to give the best user experience, monitor the site performance, offer social networks features, or display advertisements. By clicking "ACCEPT", you consent to the use of cookies in accordance to our privacy policy.