Omega-3 fats for fertility, pregnancy and postpartum
Omega-3 fats are often hailed as a nutritional powerhouse, and for good reason—they play a pivotal role in every stage of the reproductive journey. From boosting fertility to supporting your baby’s brain and eye development during pregnancy, to aiding postpartum recovery—these essential fats are key to you and your baby’s health.
But with so much conflicting advice about food sources and supplements, it can be overwhelming to figure out which omega-3 fats are best and how to incorporate them into your diet. So let’s dive in…
What are omega-3 fats?
Omega-3 fatty acids are a type of polyunsaturated fat. They’re considered "essential" fats because our bodies cannot produce them, meaning we must obtain them through diet or supplementation.
The most common omega-3 fats are:
ALA (alpha-linolenic acid)
EPA (eicosapentaenoic acid)
DHA (docosahexaenoic acid)
However, they are not created equal. Our bodies prefer omega-3 fats in their long chain form, as this is where we see the most health benefits.
ALA is a “short chain” omega-3 fat.
EPA and DHA are “long chain” omega-3 fats.
ALA
These fats are often referred to as "plant-based" omega-3 fats, because plants are where they are most abundant in our diet. ALA is a precursor for the superior fats EPA and DHA, however humans are not very good at this conversion, with studies estimating that less than 10% of ALA is converted to EPA and even less into DHA.(1,2) This conversion is even worse in people who have diets high in omega-6 fats (common in a typical Western diet). This means we can not rely on ALA to provide us with adequate amounts of long chain omega-3 fats. When ALA is not converted to EPA or DHA, it is simply stored or used as energy like other fats.
That being said, there are health benefits to including ALA rich foods in your diet:
They are usually bundled up in foods that contain fibre, antioxidants and protein.
The right sources of ALA rich foods may improve your omega-6 to omega-3 ratio. The lower the ratio, the less inflammation.
EPA and DHA
These long chain omega-3 fats are as good as they get! High intakes of EPA and DHA come with many health benefits, not just when it comes to reproductive health (which we will cover in this blog), but also cardiovascular health and our mental health. They have the biggest impact on our omega-6 to omega-3 ratio, and hence they reduce inflammation in the body.
Benefits of omega-3 fats for fertility, pregnancy and postpartum
FERTILITY
Omega-3 fats support fertility by:
Improving hormonal balance.
Enhancing egg and sperm quality.
Supporting embryo implantation and menstrual cycle function.
A 2024 study found that omega-3 intake (via supplements or fish consumption) may improve pregnancy and fertilisation rates.(3) Omega-3s may also delay ovarian aging and improve egg quality in women of advanced maternal age.(4) For men, omega-3 fats are associated with improved sperm motility and morphology.
PREGNANCY
During pregnancy, omega-3 fats are vital for:
The development of your baby's brain, eyes, and nervous system.(5) DHA, in particular, is highly concentrated in the brain and retina.
Reducing the risk of preterm birth, low birth weight, perinatal death and neonatal care admission.(6) Adequate omega-3 intake during pregnancy may reduce the likelihood of these adverse outcomes by supporting healthy placental function and reducing inflammation.
POSTPARTUM
Omega-3 fats may reduce the risk of postpartum depression by supporting brain function and mood regulation. Low DHA levels during pregnancy and postpartum have been linked to an increased risk of depression.(7) Studies have found that supplementing with long chain omega-3s during pregnancy or postpartum reduces some symptoms associated with depression.(8)
Food sources of omega-3 fats
ALA-rich foods
Foods that are rich in ALA without being too high in omega-6 fats will provide the most benefits from an anti-inflammatory perspective. These include:
Chia seeds
Hemp seeds
Walnuts
Flaxseeds
Red kidney beans
Pumpkin seeds
DHA and EPA-rich foods
The best sources of long-chain omega-3 fats are caviar and oily fish:
Caviar (fish eggs): 6000 mg per 100 g
Mackerel: 2000-4000 mg per 100 g
Herring: 2000 mg per 100 g
Salmon: 1800-2000 mg per 100 g
Sardines: 1500 mg per 100 g
Rainbow trout: 1000 mg per 100 g
Other sources include mussels, oysters, scallops, tinned tuna, eggs and grass fed beef, though their omega-3 content is much lower. All of these seafood options are low in mercury, making them safe for pregnancy. You can learn more about mercury in pregnancy in our book, Nurture the Seed.
Note: 115 g of raw fish will equal roughly 100 g of cooked fish
How much omega-3 do you need?
Recommendations for omega-3 intake vary widely.
Australia’s Nutrient Reference Values:(9)
Non-pregnant: 90 mg/day (160 mg/day for men)
Pregnant: 115 mg/day
Lactation: 145 mg/day
This guideline has not been updated since 2006 and is terribly low compared to other organisations.
The International Society of Fatty Acids and Lipids (ISSFAL) recommends a minimum of 200 mg/day of DHA for pregnant women, while other organisations recommend between 400 - 1000 mg/day.(10,11)
One thing that is agreed upon, however, is that we should aim for 2-3 serves of oily fish/week (1 serve = 100g). This works out, on average, at approximately 500 mg of DHA+EPA per day.
If you are unsure if you are getting enough, you can test your omega-3 levels through private laboratories. I recently did this myself and found the results really interesting. Take a look here if you like.
Do you need an omega-3 supplement?
Omega-3 supplements are becoming increasingly popular, but do you need one? This depends on your diet and your health status.
If you don’t eat oily fish: A supplement is recommended to ensure adequate intake. A starting dose of 500 mg DHA+EPA daily is typically sufficient for most women.
Therapeutic needs: For women trying to conceive or people with cardiovascular risk factors, higher doses may be required. Please note that high doses are not recommended in the third trimester of pregnancy due to potential blood-thinning effects.
Always consult a healthcare provider or prenatal dietitian before supplementing your diet. At Renee Jennings Dietitian, we offer Supplement Packages tailored to your needs. Learn more about them here.
Want More Support?
You can explore more about omega-3 fats and other nutrients like iron and folate in our pregnancy book, Nurture the Seed. You’ll also find many delicious recipes to help you incorporate these nutrients into your diet.
References:
Brenna JT. Efficiency of conversion of alpha-linolenic acid to long chain n-3 fatty acids in man. Curr Opin Clin Nutr Metab Care. 2002 Mar;5(2):127-32. doi: 10.1097/00075197-200203000-00002. PMID: 11844977.
Gerster H. Can adults adequately convert alpha-linolenic acid (18:3n-3) to eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3)? Int J Vitam Nutr Res. 1998;68(3):159-73. PMID: 9637947.
Shivtia Trop-Steinberg, Michael Gal, Yehudith Azar, Rachel Kilav-Levin, Eliyahu M. Heifetz, Effect of omega-3 supplements or diets on fertility in women: A meta-analysis, Heliyon, Volume 10, Issue 8, 2024, e29324, ISSN 2405-8440, https://doi.org/10.1016/j.heliyon.2024.e29324.
Nehra, D., Le, H.D., Fallon, E.M., Carlson, S.J., Woods, D., White, Y.A., Pan, A.H., Guo, L., Rodig, S.J., Tilly, J.L., Rueda, B.R. and Puder, M. (2012), Prolonging the female reproductive lifespan and improving egg quality with dietary omega-3 fatty acids. Aging Cell, 11: 1046-1054. https://doi.org/10.1111/acel.12006
Coletta JM, Bell SJ, Roman AS. Omega-3 Fatty acids and pregnancy. Rev Obstet Gynecol. 2010 Fall;3(4):163-71. PMID: 21364848; PMCID: PMC3046737.
Middleton P, Gomersall JC, Gould JF, Shepherd E, Olsen SF, Makrides M. Omega‐3 fatty acid addition during pregnancy. Cochrane Database of Systematic Reviews 2018, Issue 11. Art. No.: CD003402. DOI: 10.1002/14651858.CD003402.pub3. Accessed 10 December 2024.
Markhus MW, Skotheim S, Graff IE, Frøyland L, Braarud HC, Stormark KM, Malde MK. Low omega-3 index in pregnancy is a possible biological risk factor for postpartum depression. PLoS One. 2013 Jul 3;8(7):e67617. doi: 10.1371/journal.pone.0067617. PMID: 23844041; PMCID: PMC3701051.
Hsu MC, Tung CY, Chen HE. Omega-3 polyunsaturated fatty acid supplementation in prevention and treatment of maternal depression: Putative mechanism and recommendation. J Affect Disord. 2018 Oct 1;238:47-61. doi: 10.1016/j.jad.2018.05.018. Epub 2018 May 16. PMID: 29860183.
Australian Government National Health and Medical Research Council, Eat For Health, Nutrient Reference Values for Australia and New Zealand, https://www.eatforhealth.gov.au/nutrient-reference-values/nutrients/fats-total-fat-fatty-acids, accessed 12/12/24.
ISSFAL, GOED Global recommendations for EPA and DHA intake, revised 2014, https://www.issfal.org/assets/globalrecommendationssummary19nov2014landscape_-3-.pdf
Koletzko B, Cetin I, Brenna JT; Perinatal Lipid Intake Working Group; Child Health Foundation; Diabetic Pregnancy Study Group; European Association of Perinatal Medicine; European Association of Perinatal Medicine; European Society for Clinical Nutrition and Metabolism; European Society for Paediatric Gastroenterology, Hepatology and Nutrition, Committee on Nutrition; International Federation of Placenta Associations; International Society for the Study of Fatty Acids and Lipids. Dietary fat intakes for pregnant and lactating women. Br J Nutr. 2007 Nov;98(5):873-7. doi: 10.1017/S0007114507764747. Epub 2007 Aug 10. PMID: 17688705.
