DHA & pregnancy factsheet

You know DHA omega-3 is good for you, but do you want to know why?

Pregnant and nursing women make important dietary decisions every day by consuming a healthy diet that includes essential perinatal nutrients such as folic acid and calcium. The science supporting the importance of these nutrients during childbearing years is well established, yet emerging science suggests there is another nutrient, DHA omega-3 (docosahexaenoic acid), that pregnant and nursing women should consider adding to their diet.

DHA omega-3 is found throughout the body, but is most abundant in the brain, eyes and heart. In fact, DHA represents about 97 percent of all omega-3 fats in the brain and 93 percent of all omega-3 fats in the retina in the eye. DHA accumulates both prenatally and postnatally in infant brain, eye and nervous system tissue. Developing infants cannot efficiently produce their own DHA and must obtain this vital nutrient through the placenta during pregnancy and from breast milk following birth. Increasing DHA in the diet during pregnancy and nursing significantly enhances the level of DHA available to the unborn baby and infant.

What are the benefits of DHA in pregnancy?

Recent EU expert conclusions indicate that DHA is important for optimal infant brain and eye development. DHA is important throughout pregnancy, particularly in the third trimester when major brain growth occurs. Increasing DHA intake during pregnancy and nursing significantly enhances the level of DHA available to the foetus and infant. Certain studies (some, but not all) have shown that supplementation of DHA in the mother’s diet improves infant developmental outcomes, such as:

  • eye-hand coordination
  • motor skills
  • attention span

DHA has also been shown to play a part in maternal well-being. Studies show that supplementation of DHA in the mother’s diet can increase the length of pregnancy by six days helping mothers carry to a healthy or full term.

How much DHA is needed in pregnancy?

A woman’s DHA levels are diet dependant. Women of childbearing age who consume a typical Western diet are at risk of low stores of DHA. This is because the primary dietary sources of DHA are fatty fish and organ meats, dietary choices that are not staples of the typical Western diet. Additionally, experts often advise pregnant and nursing women to limit their fish consumption due to the potentially high levels of toxins such as mercury.

As awareness of the importance of DHA grows, more attention is being paid to the fact that pregnant and breastfeeding women may benefit from getting more DHA in their diets. In fact, the EFSA Scientific Panel recommends that pregnant and nursing women should consume an additional 100-200 mg DHA daily in addition to the 250 mg omega-3 intake recommended by EFSA for adults. One expert body even recommends that pregnant and nursing women consume 300mg of DHA per day, which is well above the typical daily intake of less than 100mg DHA. A growing understanding of the dietary sources of DHA and the inclusion of DHA into a growing number of prenatal supplements are making it easier for women of childbearing age to include this important nutrient in their diets every day.

What are the dietary sources of DHA?

Dietary sources of DHA include:

  • Algae - Certain microalgae are natural sources of DHA. While most people believe that fish produce their own DHA, in fact, it’s the algae they feed on that make them a rich source of DHA. A natural vegetarian source of DHA can now be produced from microalgae and is currently available in dietary supplements, fortified foods, and a number of infant formulas sold worldwide.
  • Fatty fish including anchovies, salmon, herring, mackerel, tuna and halibut
  • Organ meat such as liver
  • Fish oil
  • Small amounts are found in poultry and egg yolks
  • There is a common misconception that flaxseed oil is a dietary source of DHA. However, flaxseed oil is a source of alpha-linolenic acid, ALA, a precursor of DHA. ALA has no known independent benefits on brain or eye development and function, compared to DHA. Although the human body can convert ALA to DHA, the process is inefficient and variable.

Is there risk in eating oily fish?

Oily fish is one of the richest natural dietary sources of DHA. However, women who are trying for a baby or who are already pregnant should eat no more than two portions every week, of which one should be oily fish, according to guidelines from the UK Food Standard Agency.

These guidelines come in response to findings that certain fish contain mercury, a contaminant that when present at high levels could harm the developing nervous system of fetuses, newborns and young children. To minimize the risk of mercury exposure, pregnant women, women who may become pregnant, nursing mothers and young children should eat no more than 12 ounces of cooked fish per week and choose a variety of fish rather than a single type. Pregnant women have also been warned to avoid shark, swordfish and marlin, which are at the top of the food chain and therefore have higher levels of these toxins.

What are the best alternative sources of DHA?

Many people believe that flaxseed oil is a good source of DHA, but flaxseed oil is a dietary source of alpha-linolenic acid (ALA), a precursor of DHA. The body can make small amounts of DHA from ALA, but this process is inefficient and variable. Therefore, if you are looking for the benefits of DHA, it is best to consume it directly.

For non-fish eaters, microalgae supplements, such as life’sDHA™, are a vegetarian source rich in DHA and a useful way of increasing DHA omega-3 intake. Further information on sources of omega-3 fatty acids is available from the British Nutrition Foundation’s website, www.nutrition.org.uk.