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NIH Record - National Institutes of Health

NIH-Funded Study Finds Higher Dose of DHA Lowers Preterm Birth Risk

A pregnant woman holds a dietary supplement pill

A higher dose of DHA in the last half of pregnancy may reduce risk of early preterm birth.


Women taking 1,000 mg of docosohexanoic acid (DHA) daily in the last half of pregnancy had a lower rate of early preterm birth than women who took the standard 200 mg dose, according to an NICHD-funded study that appears in EClinicalMedicine. Women given the higher dose who entered the study with a low DHA level had the greatest reduction in early preterm birth, defined as birth before 34 weeks of pregnancy, which increases the risk of infant death and disability.

Previous studies on the potential effects of DHA and other omega-3 fatty acids—nutrients found in fish and eggs and supplements like algal oil—have been inconclusive and have not identified a specific type or dose of omega-3 fatty acids.

Researchers enrolled nearly 1,100 women and compared the effects of administering 1,000 mg of DHA in one group and 200 mg in another group on the early preterm birth rate. Overall, fewer women in the high-dose group delivered early preterm compared to the standard-dose group. Among women who had high DHA levels at study entry, the rate of early preterm birth was low and did not differ by dose. The authors called for screening DHA levels in pregnancy so that women with low levels could consider taking a higher daily dose.

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