DHA and Omega-3s for Fertility: The Science

DHA shows up on prenatal labels, in fertility forums, and in nearly every “egg quality” supplement list. It is one of the most common questions our community asks about. So what does the science actually say? Research on omega-3s for fertility is promising in some areas and still uncertain in others. This guide explains what omega-3s are, what studies suggest for women and men trying to conceive, and how to get enough safely.

This article is for education only and is not medical advice. Please talk with your doctor before starting fish oil or any supplement, especially if you take blood thinners or have a procedure coming up. As an Amazon Associate, Fertility Mommies earns from qualifying purchases, at no extra cost to you.

What are omega-3 fatty acids?

Omega-3s are a family of polyunsaturated fats that your body needs but cannot make in large amounts on its own. The three main types are:

• ALA (alpha-linolenic acid): found in plant foods like flaxseed, chia seeds, walnuts, and canola oil. The body converts only a small amount of ALA into EPA and DHA.
• EPA (eicosapentaenoic acid): found mainly in fatty fish and fish oil. It plays a role in regulating inflammation.
• DHA (docosahexaenoic acid): also found in fatty fish and algae. It is a major building block of the brain and the retina of the eye.

Because ALA conversion is limited, fish, seafood, and algae are the most direct sources of EPA and DHA.

Why DHA matters in pregnancy

DHA’s role in pregnancy is the best-established part of the story. It accumulates in the developing baby’s brain and eyes, especially in the later stages of pregnancy. That is why many prenatal vitamins include DHA or recommend a separate supplement, and why health authorities encourage eating low-mercury seafood during pregnancy. Starting good habits before conception means your intake is already steady when you need it most.

Omega-3s for fertility: what research shows

For women

Some observational studies have linked higher omega-3 intake or blood levels with markers of better reproductive health, and some research in IVF patients has looked at associations with embryo quality or pregnancy rates. However, observational studies cannot prove cause and effect, and high-quality trials showing that omega-3 supplements increase pregnancy or live birth rates are limited. Our overview of the latest research on egg quality supplements puts this in context.

For men

Sperm cell membranes are rich in DHA. Some studies suggest omega-3 supplementation may improve certain semen parameters, such as motility, but results vary and it is not clear whether this translates into more pregnancies. For more, see our guide to men’s supplements for sperm quality.

Inflammation and overall health

Omega-3s help regulate inflammation and support heart health. A diet rich in omega-3s, such as the Mediterranean pattern, is associated with better overall health, which is a good foundation for fertility. Read more in what research shows about the fertility diet.

Best food sources of omega-3s

Fatty fish are the richest sources of EPA and DHA. Choose low-mercury options such as:

• Salmon
• Sardines
• Anchovies
• Trout
• Herring
• Atlantic mackerel (not king mackerel)

U.S. food safety guidance encourages people who are pregnant or might become pregnant to eat 8 to 12 ounces per week of a variety of low-mercury seafood. Avoid high-mercury fish such as shark, swordfish, king mackerel, tilefish from the Gulf of Mexico, bigeye tuna, marlin, and orange roughy.

Plant sources of ALA include ground flaxseed, chia seeds, walnuts, hemp seeds, and soybeans. Sprinkle ground flaxseed or chia on oatmeal, yogurt, or smoothies. For meal ideas, browse our omega-3-rich recipes for fertility.

Should you take an omega-3 supplement?

If you rarely eat fish, a supplement may help you get enough DHA. Many people choose a prenatal that already contains DHA or add a separate prenatal DHA supplement. If you are vegetarian or vegan, an algae-based omega-3 provides DHA without fish. Your doctor can help you decide what you need.

Choosing a quality supplement

• Look for third-party testing for purity and contaminants
• Check the amount of DHA and EPA per serving, not just “fish oil”
• Store as directed to prevent the oil from going rancid
• Avoid cod liver oil unless your doctor approves, since it contains vitamin A, which can be harmful in high amounts during pregnancy

Safety considerations

Omega-3 supplements are generally well tolerated. Side effects can include fishy aftertaste, burping, or an upset stomach. Higher doses may affect blood clotting, so tell your doctor if you take blood thinners or have a procedure such as an egg retrieval scheduled.

Frequently asked questions

Can omega-3s improve egg quality?

Some early research is interesting, but there is not enough strong evidence to say omega-3 supplements improve egg quality. They are still a healthy part of a balanced diet.

Is canned tuna safe while trying to conceive?

Canned light tuna is generally considered a lower-mercury choice. Albacore tuna has more mercury, so current guidance recommends eating it less often. Check current FDA advice for details.

Do I need DHA if my prenatal already has it?

Possibly not. Check the label and ask your doctor whether the amount fits your diet.

The bottom line

DHA and omega-3s are clearly important for pregnancy and overall health, and they may play a supportive role in fertility for both partners, though the research is still developing. Eat low-mercury fatty fish regularly or choose a quality supplement with your doctor’s input, and see it as one helpful piece of a healthy routine.