Paging Dr. Grunebaum: Prenatal Vitamins, Part 2: What’s the Deal with Omega-3’s?

Today wraps up our two-part series on prenatal vitamins with Dr. Grunebaum  of BabyMed.com, Director of Obstetrics and Chief of Labor & Delivery at NewYork-Presbyterian Hospital/Weill Cornell Medical Center.  Yesterday, he gave us an overview of prenatal vitamins.  Today he fills us in on the newest studies on DHA and EPA – and why you shouldn’t rely on your prenatals for these incredibly important nutrients.

What are Omega-3 Fatty Acids?

Omega-3 fatty acids are chemicals that are essential for the development of important body functions. Most omega-3 acids are consumed in the diet but they can also be added to the diet with supplements.

During pregnancy, getting enough omega-3 fatty acids is crucial because these fatty acids are critical building blocks of the fetal brain and the retina, a part of the eye.

In addition to affecting the fetus, omega-3 fatty acids may also play a role in determining the length of gestation and in preventing postpartum depression.

There are two fatty acids that are especially important:

• DHA: Docosahexaenoic acid (DHA) and
• EPA: Eicosapentaenoic acid (EPA)

In general, omega-3 fatty acids are associated with several different body functions such as dilatation of vessels, preventing blood clots, and reduction in inflammation.  DHA is also a fatty acid that is mostly located in the brain, and it especially increases in the brain of the fetus very quickly in the third trimester of the pregnancy. Maternal nutrition has a significant effect on the developing fetus and having the proper amount of omega-3 affects the amount of DHA deposited in the growing brain.

How can you get these fatty acids?

In general, these fatty acids are found in plants such as walnuts and in oils made from soy, canola, and flaxseed. In addition, both DHA and EPA are found in fatty fish (salmon, tuna, trout, sardines, and mackerel) and in smaller amounts in lean fish and shrimp. Your diet should therefore be geared towards getting these foods within a balanced diet.  You can also get these through prenatal supplements, but note that many, many prenatal vitamins do NOT contain these important fatty acids.  Therefore diet is especially important.

Many seafoods are rich in Omega-3, however about 10 years ago the FDA  advised all pregnant women to limit seafood consumption to 340 g (2 6-oz servings) per week to limit fetal exposure to trace amounts of potential toxins such as mercury. Pregnant women should continue to eat 2 servings of fish and seafood a week during pregnancy, but they should avoid consumption of swordfish, king mackerel, shark, and tilefish.

Observational studies have found that omega-3 fatty acid consumption during pregnancy either in the diet or via supplements is associated with improved neurodevelopmental outcomes in the child, but there is not enough data to recommend omega-3 fatty acid supplementation for the sole purpose of prolonging gestation or reducing the risk of preterm birth.

In addition, some data have shown that low seafood intake during pregnancy correlates with higher levels of depressive symptoms during pregnancy even while  more thorough randomized, controlled trials have failed to demonstrate a clear benefit to omega-3 fatty acid supplementation during pregnancy and postpartum to prevent depressive symptoms.

Recommendation

Omega-3 fatty acids are essential for the developing fetus. All pregnant women should try to eat the right amount of food to obtain omega-3 in pregnancy.  The right food includes 2 servings of low mercury seafood, plants, or supplements.

As a good alternative, especially if you cannot consume the recommended amount of seafood, you can get the right amount of omega-3 fatty acids from fish oil supplements. Because omega-3 supplements are usually made from low mercury fish oil they are safe augment omega-3 fatty acids in the diet.  However, many prenatals do not contain these supplements.  If you need to supplement your diet, be sure to check your prenatal vitamins and make sure that they include these fatty acids or, alternatively, use a separate supplement.