Sydney, Nov 16 (IANS): Increasing the intake of omega-3 fatty acids during pregnancy reduces the risk of premature births, says a new research.

While the length of most pregnancies is between 38 and 42 weeks, the earlier a baby is born, the greater the risk of death or poor health.

Premature babies are at higher risk of a range of long-term conditions including visual impairment, developmental delay and learning difficulties.

The findings showed that increasing the daily intake of long-chain omega-3s lowered the risk of having a premature baby (less than 37 weeks) by 11 per cent (from 134 per 1,000 to 119 per 1,000 births).

It also lowered the risk of having an early premature baby (less than 34 weeks) by 42 per cent (from 46 per 1,000 to 27 per 1,000 births) as well as decreased the risk of having a small baby by 10 per cent.

"There are not many options for preventing premature birth, so these new findings are very important for pregnant women, babies and the health professionals who care for them," said Philippa Middleton, Associate Professor from the South Australian Health and Medical Research Institute (SAHMRI).

"We don't yet fully understand the causes of premature labour, so predicting and preventing early birth has always been a challenge. This is one of the reasons omega-3 supplementation in pregnancy is of such great interest to researchers around the world."

For the study, published in the journal Cochrane Database of Systematic Reviews, the team looked at 70 randomised trials involving 19,927 women at low, mixed or high risk of poor pregnancy outcomes.

The optimum dose was a daily supplement containing between 500 and 1,000 milligrams of long-chain omega-3 fats (containing at least 500mg of DHA) starting at 12 weeks of pregnancy.

Premature birth, a critical global health issue and the leading cause of death for children under five years old worldwide, accounts for close to 1 million deaths annually.