Fish is one of the healthiest foods you can include during pregnancy, offering protein and important omega-3 fats for your baby’s development. At the same time, you may have heard that some fish are best limited because of mercury. Both things are true, and the reassuring news is that you can still enjoy fish safely with a little know-how. This article explains why fish matters in pregnancy, which types to limit because of mercury, how much is safe, and how to make confident choices at the fish counter.
TLDR
Fish is a nutritional powerhouse, and it has a valuable place in a healthy pregnancy diet. Rather than avoiding it, most women are encouraged to include it regularly. Understanding what fish offers helps explain why it is worth keeping on the menu.
Fish is a great source of high-quality protein, which supports your baby’s growth. It also provides iodine, which is important for your baby’s brain development, along with other nutrients like vitamin D and selenium. These nutrients can be harder to get in the right amounts from other foods, which is part of what makes fish so valuable in pregnancy.
Oily fish are rich in long-chain omega-3 fats, particularly DHA, which supports your baby’s brain and eye development. These are the same healthy fats linked with heart health more broadly. Including oily fish such as salmon and sardines is one of the easiest ways to boost your omega-3 intake during pregnancy.
Because of these benefits, health authorities advise that there is no need for pregnant women to stop eating fish altogether (Food Standards Australia New Zealand, accessed September 2026). The aim is simply to choose lower-mercury fish most of the time. If you would like guidance, pregnancy and women’s health nutrition support can help you get the balance right.
Mercury is a naturally occurring element that finds its way into waterways and, in small amounts, into fish. It is present at low levels in most fish, which is why the vast majority are perfectly safe to eat. The consideration in pregnancy is only with the fish that carry more.
The pattern is fairly simple. Large fish that live a long time, and predatory fish that eat other fish, tend to accumulate more mercury. This is why species like swordfish and shark are higher, while smaller, shorter-lived fish are lower. High levels of mercury can affect a developing baby’s nervous system, which is why the advice exists.
This does not mean fish is risky. It means choosing wisely, favouring the many lower-mercury options and limiting the few higher-mercury ones.
Australian food safety advice groups fish into a few simple categories based on their mercury levels (NSW Food Authority, accessed September 2026). The table below shows the fish to limit, and how often, during pregnancy.
Fish | How often in pregnancy |
Shark (flake), broadbill, marlin, swordfish | 1 serve per fortnight, and no other fish that fortnight |
Orange roughy (sea perch), catfish | 1 serve per week, and no other fish that week |
Most other fish, such as salmon and sardines | 2 to 3 serves per week |
The highest-mercury group includes shark (often sold as flake), broadbill, marlin and swordfish. If you choose one of these, the advice is to have no more than one serve per fortnight, and to eat no other fish during that fortnight. For many women, it is easiest to simply choose lower-mercury options instead.
Orange roughy, also sold as sea perch, and catfish sit in a middle group. These can be eaten up to once per week, with no other fish that week. They are fine as an occasional choice, but they are not the best pick for your regular fish meals during pregnancy.
The reassuring news is that most fish are low in mercury and can be enjoyed regularly. Good everyday choices include:
Building your fish meals around these options lets you enjoy the benefits with peace of mind. Cooked, well-prepared fish is the safest choice, as raw fish carries other pregnancy considerations separate from mercury.
For most fish, the advice is reassuringly generous. It is safe to eat two to three serves of most types of fish each week, where a serve is about 150 grams, or roughly two crumbed fish portions. This easily covers a couple of fish meals a week for most women.
The limits only apply to the higher-mercury fish above. As long as you are choosing lower-mercury options, you can comfortably meet the two to three serve recommendation and give yourself and your baby the benefits of fish.
If you are unsure about a particular fish, or you tend to eat a lot of one type, it is worth checking the guidance or asking a health professional. Variety is your friend, both for nutrition and for keeping mercury intake low.
Pregnancy nutrition covers far more than fish, and it can feel like a lot to take in. An Accredited Practising Dietitian can help you put it all together into a balanced, enjoyable eating pattern that supports you and your baby.
A dietitian can also help with common pregnancy experiences, from meeting your nutrient needs to managing nausea, reflux or changes in digestion. Where helpful, gut and digestive support can make everyday eating more comfortable during pregnancy.
Support is practical and individualised, working alongside your GP and midwife so your care is joined up. Small, realistic changes make healthy eating feel achievable, even when pregnancy has its ups and downs.
Fish can be a healthy, enjoyable part of your pregnancy when you know which types to limit and which to enjoy. If you would like tailored guidance on eating well through pregnancy, An Accredited Practising Dietitian at Body Fusion can help you build a plan that suits you, in person across our Sydney clinics or by telehealth.
This article is general information only and is not a substitute for personalised medical or dietetic advice. For guidance on your individual pregnancy and diet, please speak with your GP, midwife or an Accredited Practising Dietitian.
