The Importance of Omega-3 Fatty Acids in Pregnancy
How important are omega-3 fatty acids in a pregnant woman’s diet?
Pregnant women are advised to eat about 12 ounces of fish a week, including one of oily fish. Raw fish or seafood, swordfish, tilefish, king mackerel, and shark are best avoided due to risk of food poisoning and heavy metal toxicity.
Eating fish is good for general health, but particular importance is placed on the omega-3 fatty acids in oily fish for maternal and fetal health. They are believed to bring a range of benefits such as helping the baby’s visual and nervous systems to develop.
Omega-3 fats are a particular class of “healthy” fats, found in certain nuts and seeds (as alpha-linolenic acid) and in oily fish such as salmon, trout and sardines (as eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA).
A 2007 study of 11,875 pregnant women, published in the medical journal Lancet, showed that eating more than 340 grams (12 ounces) of seafood a week — the equivalent of about two and a half portions — is beneficial to the child’s neurodevelopment. It also suggested that eating less than this amount may bring an increased risk of lower verbal intelligence and social development.
The researchers write, “We recorded beneficial effects on child development with maternal seafood intakes of more than 340 g per week. These results show that risks from the loss of nutrients were greater than the risks of harm from exposure to trace contaminants.”
Professor Michael Crawford of London Metropolitan University, UK, comments, “Unlike the rest of the body, the brain is mainly made of fat. It needs these fatty acids for brain growth and development. We are deeply concerned that this has been more or less neglected in the current advice and unless there is a change in nutrition advice to take the brain into account, then mental disorders are going to continue to grow at an alarming rate.”
Other research has linked inadequate omega-3 intake with an increased risk of low birth weight. A study based on 700 women in India found that not eating fish at all during pregnancy was associated with a 2.5-fold increased risk of low birth weight. Added to the other likely benefits of omega-3 consumption during pregnancy, this does support the argument for ensuring adequate levels during gestation.