A new Cochrane Review analyzing 70 clinical trials and nearly 20,000 pregnant women has brought powerful clarity to a long-standing question: Can omega-3 fatty acids reduce the risk of preterm birth?
The answer, according to the evidence, is a resounding yes. Omega-3 supplementation during pregnancy — particularly long-chain fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) — significantly lowers the risk of preterm and early preterm birth, as well as other serious complications.
Key Findings from the Cochrane Review
The updated review builds on decades of research, and its conclusions are remarkably consistent across studies:
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Preterm birth (<37 weeks): Risk reduced by 11%
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Early preterm birth (<34 weeks): Risk reduced by 42%
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Low birthweight (<2500 g): Risk reduced by 10%
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Perinatal death: Risk reduced by 25%
These findings demonstrate that omega-3s can be a simple, safe, and cost-effective strategy for improving pregnancy outcomes globally.
“Supplementation during pregnancy is a simple and effective way to reduce preterm, early preterm birth and low birthweight, with low cost and little indication of harm,” researchers concluded.
Why Omega-3s Matter During Pregnancy
Premature birth remains the leading cause of death in children under five, accounting for nearly one million deaths each year. Beyond survival, premature babies face higher risks of developmental delays, learning difficulties, and visual impairment.
Omega-3 fatty acids — found primarily in fatty fish and fish oil supplements — play a vital role in fetal development. DHA, in particular, supports brain, eye, and nervous system growth, while EPA assists in placental function and circulation.
However, most women consume far less DHA than recommended. In the U.S., for example, pregnant women average about 60 mg DHA daily, far below the minimum 200 mg recommended by experts — and only 9% take an omega-3 supplement at all.
The Optimal Omega-3 Dosage for Pregnancy
The Cochrane Review suggests the most effective range is between 500–1000 mg of long-chain omega-3s daily, containing at least 500 mg DHA, starting around the 12th week of pregnancy.
Current and upcoming trials — such as the ORIP and ADORE studies — are exploring whether higher doses (800–1000 mg DHA daily) may provide even stronger protection.
“A universal strategy of supplementation may be reasonable,” said Dr. Kristina Harris Jackson, research associate at OmegaQuant, “although ideally, with more knowledge, this would be targeted to women who would benefit the most — likely those with low DHA blood levels.”
The Biological Advantage of Omega-3s
Among the 70 studies analyzed, most were dedicated to pure omega-3 or DHA supplementation — reinforcing that the benefits stem from the biological activity of omega-3s themselves, rather than whole fish consumption alone.
According to Dr. Harris Jackson, this distinction underscores how DHA-rich supplements can directly support maternal and fetal health, especially for those who struggle to consume enough fish.
Safety and Global Implications
Omega-3 supplements have an excellent safety profile, making them one of the few proven and low-risk interventions for reducing preterm birth. The Cochrane team emphasized that further placebo-controlled trials are unnecessary, urging health professionals to focus instead on implementation and population-specific strategies.
Associate Professor Philippa Middleton of Cochrane Pregnancy and Childbirth summarized:
“There are not many options for preventing premature birth, so these findings are very important for pregnant women, babies, and the health professionals who care for them.”
Remaining Questions and Future Research
While the benefits of omega-3s for preterm birth are well-established, some areas — such as maternal mental health and child cognitive outcomes — require further investigation. Most included trials were conducted in high- and middle-income countries, so additional studies in diverse populations will help refine global recommendations.
Future research should also explore:
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Differences in response based on baseline DHA levels
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Timing and duration of supplementation
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Long-term effects on child growth and neurodevelopment
The Bottom Line
This comprehensive meta-analysis provides the strongest evidence yet that omega-3 supplementation during pregnancy can dramatically improve birth outcomes — reducing the risk of early birth, low birthweight, and perinatal complications.
For expectant mothers, this is welcome news: a simple, affordable, and safe way to protect both mom and baby.
Experts now recommend at least 200–500 mg DHA per day, ideally through a high-quality fish oil supplement or increased intake of fatty fish with low mercury content.
As Dr. Harris Jackson puts it, “We need to fill the gap.”
References
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Middleton P. et al., Cochrane Review: Omega-3 fatty acids for preventing preterm birth (2023 update).
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Harris Jackson K., OmegaQuant Research Insights on Omega-3s and Pregnancy.
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National Center for Biotechnology Information.
