Omega 3 Fatty Acids and Pregnancy

By:  Lisa Moloney MS, RD, LDN

It is well documented that omega 3 fatty acids EPA and DHA are beneficial for pregnant and lactating women.  DHA is particularly important for infant brain development and maturation.   Studies have shown that infants born to mothers with higher blood levels of the omega-3 fatty acid DHA at delivery had advanced cognitive function and increased attention spans well into their second year of life. In 2007 the American Dietetic Association recommended a minimum for 500mg/day of EPA and DHA for adults.  The daily target for particularly DHA intakes during pregnancy, including the last trimester wherein DHA is very actively deposited in the brain membrane phospholipids, should be 300 mg/day.

Fish is the primary food source of omega-3s EPA and DHA.  There is a legitimate concern about avoiding fish due to
mercury.  Fish should not be cut out of the diet, however, because it contains many healthy nutrients that are essential for growth and development.  The FDA has released guidelines that pregnant women should consume no more than 12 oz of low mercury fish.  “Highest” mercury fish should be avoided and “high” mercury fish should be kept to only three 6 oz servings per month.  Please see the list below provided by the American Pregnancy Association to help calculate your totals.

The current estimated daily intake of EPA and DHA amongst pregnant women in North America is approximately 80 mg/day.  This leaves a gap of 420mg/day requiring supplementation for most pregnant women.  With fish oil pills, look for varieties that are as concentrated as possible. Vegetarians can get the same benefits from algae-based supplements, which are also the kind that appear in some infant formulas.

Highest Mercury

AVOID Eating

• Marlin
• Orange roughy
• Tilefish
• Swordfish
• Shark
• Mackerel (king)
• Tuna ( bigeye, Ahi)

High Mercury

Eat no more than three 6-oz servings per month

• Sea Bass (Chilean)
• Bluefish
• Grouper
• Mackeral ( Spanish, Gulf)
• Tuna (canned, white albacore) See tuna chart below
• Tuna ( Yellowfin)

Lower Mercury

Eat no more than six 6-oz servings per month

• Bass ( Striped, Black)
• Carp
• Cod ( Alaskan)
• Croaker ( White Pacific)
• Halibut ( Pacific and Atlantic) Jacksmelt ( Silverside)
• Lobster
• Mahi Mahi
• Monkfish
• Perch (freshwater)
• Sablefish
• Skate
• Snapper
• Sea Trout ( Weakfish)
• Tuna (canned, chunk light)
• Tuna (Skipjack)

Lowest Mercury

Enjoy two 6-oz servings per week

• Anchovies
• Butterfish
• Catfish
• Clam
• Crab (Domestic)
• Crawfish/crayfish
• Croaker
• Flounder
• Haddock
• Hake
• Herring
• Mackeral (N Atlantic, Chub)
• Mullet
• Oysters
• Perch (ocean)
• Plaice
• Salmon ( Canned, Fresh)
• Sardines
• Scallops
• Shad ( American)
• Shrimp
• Sole
• Squid ( Calamari)
• Tilapia
• Trout (freshwater)
• Whitefish
• Whiting

Chart obtained from the Natural Resource Defense Council (NRDC); data obtained by the FDA and the EPA.