Most pregnant women in New Zealand are failing to get enough omega-3 in their diet, according to a Massey University study.
Adequate dietary intake of long-chain polyunsaturated fatty acids is needed during pregnancy to support the mother and foetus, researchers say.
They surveyed 600 pregnant women about their diet and the questionnaire was conducted in the third trimester, when eating habits are likely to be established.
Only a third consumed the recommended omega-3 intake of 200 milligrams a day, although most met the omega-6 threshold, the study, published in the NZ Medical Journal, found.
Researchers say the deficiency could be partly due to low intakes of fish, seafood and omega-3 supplements - only one in five women surveyed said they ate fish twice a week.
The study's authors say further research and interventions should focus on ways to promote optimal intakes of long chain omega-3 fatty acids during pregnancy.
They say strategies to overcome barriers to the consumption of fish and seafood during pregnancy should be explored.