Pregnant women are not getting enough omega-3

The first ever study on the intakes of omega-3 polyunsaturated fatty acids in pregnant women in New Zealand, has found only 30 per cent are getting the recommended daily amount.

A cohort of 596 pregnant women, in their last trimester of pregnancy and from all regions of New Zealand, volunteered to take part in the online study. Participants were required to complete a food frequency questionnaire, which was designed to investigate polyunsaturated fatty acid intakes over the last three months of their pregnancy.

The study was published in the New Zealand Medical Journal today.

Dr Kathryn Beck from Massey's School of Sport, Exercise and Nutrition says omega-3 fatty acids are important during pregnancy for a number of reasons. "They help form important building blocks for our cells, and are essential for the development of baby's brain and growth. These fatty acids help support mothers to have a healthy pregnancy."

The omega-3 fatty acid known as docosahexaenoic acid (DHA) is critical during the time when the neural tube closes and throughout pregnancy as it accumulates in the fetal brain and retinal tissues. The amount of DHA accumulated by the fetus occurs mainly in the third trimester of pregnancy, and is influenced by the maternal diet.

In New Zealand, the recommendation for combined omega-3 polyunsaturated fatty acids during pregnancy is 115mg per day. However, several international organisations recommend pregnant women should aim to achieve at least 200 mg of DHA per day,

Dr Beck says while 77 per cent of participants met the lower target, only 30 per cent were ingesting the international recommendations for DHA of 200mg per day.

Fish and seafood are the richest sources of omega-3 polyunsaturated fatty acids and also provide several nutrients, including protein and iodine, all of which are important for fetal development. "Two serves of fish [150g per serve] per week can substantially contribute to meeting omega-3 polyunsaturated fatty acids recommendations. Despite guidelines encouraging fish and seafood as safe to eat during pregnancy, women may decrease or limit these foods due to concerns regarding food safety and the potential for mercury poisoning," Dr Beck says.

The likely reason for the deficiency was the low intake of fish and seafood. "Women who are currently pregnant or planning to be should aim to eat a variety of healthy foods every day from each of the four food groups to get all the nutrients they need to protect the long-term health of both themselves and their baby. Those who have any concerns related to their diet should seek advice from their doctor, registered nutritionist or dietitian."

According to the Ministry of Health nutrition guidelines for pregnant women, fish and seafood can be eaten as long as they have been well cooked, served hot, and larger species are limited. Dr Beck says there is little concern with canned tuna (skipjack or albacore tuna), canned salmon, mackerel or sardines, farmed salmon, tarakihi, blue cod, hoki, john dory, monkfish, warehou, whitebait and flat fish like flounder.

"The mercury levels in these fish are seen as low risk, and their nutritional contents provide many health benefits," she says.