Increased intake of omega-3 fats during pregnancy can reduce the risk of premature birth, new research has found.

Conducted by the South Australian Health and Medical Research Institute with Adelaide's Women's and Children's Hospital and the University of Adelaide, the study shows daily omega-3 supplementation can cut the risk of birth before 37 weeks by 11 per cent and the risk of birth before 34 weeks by 42 per cent.

"This is an extremely promising finding because we now have strong evidence omega-3 supplements are a simple and cost-effective intervention to prevent premature birth, which we know has serious health implications," institute deputy director Maria Makrides said.

"Premature birth complications are the leading cause of death for children under five years of age.

"Premature babies are at greater risk of chronic issues with their respiratory, immune and digestive systems and they're more susceptible to problems with speech, social skills, learning and behaviour."

The study suggests women expecting a single baby begin taking a daily dose of omega-3s at the 12-week stage of their pregnancy.

The supplement needs to contain between 500 and 1000 milligrams of omega-3 with at least 500 milligrams of the omega-3 called DHA.

"By increasing their omega-3 intake, women can give themselves the best chance of carrying their baby to full term of 40 weeks," Prof Makrides said.

"Even a few extra days in the womb can make a substantial difference when it comes to your baby's health."

South Australian Health Minister Stephan Wade said a reduction in premature births would have widespread benefits for the community.

"Supporting premature babies in intensive care and treating ongoing challenges related to premature birth places significant pressure on families, the community and the health system," Mr Wade said.

"The evidence from this review is both exciting and compelling and something that needs to be investigated further."

The study, known as the Cochrane Review, assessed the combined results of 70 trials involving almost 20,000 women around the world.