Vital DHA: What the Research Says

Whether you’re preparing to conceive, undergoing assisted reproductive treatment (ART), pregnant, or recently postnatal, nutritional support plays a foundational role in reproductive health. One group of nutrients with extensive clinical backing is omega-3 fatty acids, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).

This article reviews the latest peer-reviewed research on omega-3s in fertility and pregnancy, offering a clear overview of why these nutrients matter — and when to consider supplementation.

What Are Omega-3s?

Omega-3 fatty acids are essential, meaning the body cannot produce them in sufficient quantities and must obtain them from diet. The most studied omega-3s are:

• Alpha-linolenic acid (ALA) – Found in plant oils such as flaxseed, soybean, and canola oil¹.
• Eicosapentaenoic acid (EPA) – Found in oily fish and marine oils².
• Docosahexaenoic acid (DHA) – Found in oily fish and microalgae².

Although the body can convert ALA to EPA and then DHA, this conversion is very limited². As a result, meaningful increases in EPA and DHA levels require direct intake from fish or supplements^14,15.

Both EPA and DHA are vital components of cell membranes, influencing membrane fluidity and nutrient transfer. DHA is especially concentrated in the brain, retina, and sperm^3,4.

Omega-3s and Preconception Health

Why Start Early?

Omega-3s help to maintain the health and integrity of the egg and sperm cell membranes. This flexibility is crucial for cellular signalling, fertilisation, and nutrient exchange. Many experts recommend beginning supplementation at least 3 months prior to trying to conceive (TTC), to support the full maturation cycle of egg and sperm cells.

DHA and EPA also have anti-inflammatory properties, which may support a more favourable environment for embryo implantation^5,6.

Improving Egg Health

A 2024 meta-analysis by Trop-Steinberg et al. reviewed 13 studies, including 1,789 women undergoing fertility treatment and 2,607 women conceiving naturally. Across both groups, omega-3 intake was associated with higher fertilisation and pregnancy rates¹⁹. Among women using ART, every study showed a pregnancy rate benefit from omega-3 supplementation.

Serum analysis confirmed that those who conceived had significantly higher omega-3 blood levels than non-pregnant counterparts¹⁹.

Separately, Hammiche et al. (2011) found that preconception omega-3 intake improved embryo morphology — an indicator of egg health and early embryonic development⁷.

Menstrual Regularity and Hormonal Balance

Omega-3s may also influence hormonal regulation and cycle regularity. In a clinical trial involving women with PCOS, omega-3 supplementation significantly improved both androgen profiles and menstrual frequency⁸.

Omega-3s and Male Fertility

Sperm cells, like egg cells, rely heavily on membrane structure and fluidity to function properly. DHA is the most abundant fatty acid in the sperm membrane and plays a critical role in sperm motility, morphology, and the fusion events required for fertilisation^3,21.

A 2019 systematic review by Falsig et al. analysed 16 studies on omega-3 fatty acid supplementation and semen quality. Of these, 14 reported a positive association between omega-3 intake and at least one semen parameter, including sperm concentration, motility, morphology, and overall sperm function²⁰.

These effects were particularly evident in infertile men and those undergoing ART. Longer durations and higher doses of omega-3 supplementation were associated with better outcomes²⁰.

Additionally, González-Ravina et al. (2018) found that supplementation with highly concentrated DHA improved several functional aspects of sperm, such as motility and membrane fusion capacity²¹.

Population studies have also linked omega-3–rich dietary patterns, such as the Mediterranean diet, to improved semen quality²⁰.

Omega-3s in Pregnancy

Once conception occurs, omega-3s—especially DHA—continue to play a central role in both maternal and infant health. DHA accumulates in the developing brain and retina of the foetus, particularly during the third trimester^3,7.

A landmark Cochrane Review (Middleton et al., 2018) evaluated the effects of omega-3 supplementation across 70 randomised controlled trials involving 19,927 women¹³. Results showed that long-chain omega-3s:

• Reduced the risk of preterm birth (<37 weeks) by 11%
• Reduced the risk of early preterm birth (<34 weeks) by 42%
• Lowered the risk of low birthweight

Omega-3s may also support maternal cardiovascular and immune health via the production of eicosanoids—signalling molecules that influence inflammation and hormone function^5,6.

Infant Neurodevelopment and Long-Term Outcomes

Evidence continues to grow linking maternal omega-3 intake to improved cognitive outcomes in offspring. A large-scale review by the National Academies of Sciences (2024), involving 29 prospective cohort studies and 102,944 mother–child pairs, found that:

• 4 oz of seafood/week was associated with improved neurocognitive development in children
• Further benefits continued up to 12 oz/week
  

Supporting studies include:

• Oken et al. (2008): Higher fish consumption in pregnancy associated with better cognition at age 3⁹³
• Hibbeln et al. (2007): Observed improved child neurodevelopment with greater maternal seafood intake in the ALSPAC cohort⁹⁴
• Oken et al. (2016): Higher prenatal fish intake linked to mid-childhood cognitive benefits⁹⁵

When and How to Supplement Omega-3s

Experts recommend beginning omega-3 supplementation at least 3 months before trying to conceive. This timeline aligns with the spermatogenesis cycle and follicular development period. Continuing through pregnancy and postnatally supports maternal stores and infant development.

A typical evidence-backed dose includes:

• DHA: ~450mg/day
• EPA: ~90–100mg/day
• Zinc: 3mg/day – for additional fertility support

Supplement sources should be fish-derived or algae-based and tested for heavy metals and contaminants.

From enhancing sperm and egg cell quality to reducing pregnancy complications and supporting early infant brain development, the research on omega-3 fatty acids—especially DHA and EPA—is compelling. Whether you’re TTC naturally, undergoing ART, or pregnant, ensuring optimal intake of these nutrients could play a meaningful role in reproductive and early-life health.

This article is for informational purposes only and does not constitute medical advice. Always speak to a healthcare provider before starting new supplements.

References

1. Institute of Medicine, Food and Nutrition Board. Dietary reference intakes for energy, carbohydrate, fibre, fat, fatty acids, cholesterol, protein, and amino acids (macronutrients). Washington, DC: National Academy Press; 2005.
2. Harris WS. Omega-3 fatty acids. In: Coates PM, Betz JM, Blackman MR, et al., eds. Encyclopedia of Dietary Supplements. 2nd ed. London and New York: Informa Healthcare; 2010:577–86.
3. Jones PJH, Rideout T. Lipids, sterols, and their metabolites. In: Ross AC, Caballero B, Cousins RJ, Tucker KL, Ziegler TR, eds. Modern Nutrition in Health and Disease. 11th ed. Lippincott Williams & Wilkins; 2014.
4. SanGiovanni JP, Chew EY. The role of omega-3 long-chain polyunsaturated fatty acids in health and disease of the retina. Prog Retin Eye Res 2005;24:87–138.
5. Jones PJH, Papamandjaris AA. Lipids: cellular metabolism. In: Erdman JW, Macdonald IA, Zeisel SH, eds. Present Knowledge in Nutrition. 10th ed. Wiley-Blackwell; 2012:132–48.
6. Shulkin M, Pimpin L, Bellinger D, et al. n-3 Fatty Acid Supplementation in Mothers, Preterm Infants, and Term Infants and Childhood Psychomotor and Visual Development: A Systematic Review and Meta-Analysis. J Nutr 2018;148:409–18.
7. Hammiche F., et al. (2011). Increased preconception omega-3 PUFA intake improves embryo morphology. Fertil Steril;95(5):1820–23. doi:10.1016/j.fertnstert.2010.11.021.
8. Nadjarzadeh A., et al. (2013). Omega-3 supplementation in PCOS. Iran J Reprod Med;11(8):665–72.
9. Lass A., Belluzzi A. (2019). Omega-3 PUFAs and IVF treatment. Reprod Biomed Online;38(1):95–99. doi:10.1016/j.rbmo.2018.10.008.
10. Trop-Steinberg S., et al. (2024). Effect of omega-3 supplements or diets on fertility in women: A meta-analysis. Heliyon;10(8). doi:10.1016/j.heliyon.2024.e29324.
11. Falsig A.-M.L., Gleerup C.S., Knudsen U.B. (2019). Omega-3s and semen quality: A systematic review. Andrology;7(6):794–803. doi:10.1111/andr.12649.
12. National Academies of Sciences, Engineering, and Medicine. The role of seafood consumption in child growth and development. Washington, D.C.; 2024.
13. Middleton P., et al. (2018). Omega-3 addition during pregnancy. Cochrane Database Syst Rev;11:Cd003402.
14. Oken E., et al. (2008). Maternal fish intake and child cognition. Am J Epidemiol;167:1171–81.
15. Oken E., et al. (2016). Prenatal fish consumption and mid-childhood cognition. Neurotoxicol Teratol;57:71–78.
16. Hibbeln JR, et al. (2007). Maternal seafood consumption and childhood neurodevelopment: ALSPAC study. Lancet;369:578–85.
17. Hibbeln JR, et al. (2019). Seafood consumption during pregnancy and neurocognitive outcomes: Systematic reviews. PLEFA;151:14–36.
18. González-Ravina C., et al. (2018). DHA supplementation and sperm function. Reprod Biol;18(3):282–88. doi:10.1016/j.repbio.2018.06.002.
19. Trop-Steinberg S., et al. (2024). Meta-analysis: Omega-3s and fertility. Heliyon;10(8).
20. Falsig A.-M.L., et al. (2019). Omega-3s and semen quality. Andrology;7(6):794–803.
21. Jones PJH, Rideout T. Lipids in cellular metabolism. In: Present Knowledge in Nutrition. 10th ed. 2012.

Please consult a healthcare professional before beginning any supplement regimen.