Eating well when you’re pregnant is one of the best things you can do for you and your baby. Whether you’ve used this time in your life to embrace a more balanced diet or were already healthy and have now developed odd cravings, your healthcare team will want to make sure you’re eating regularly and well.

Disclaimer: Please note that the following information is general guidance on nutrition in pregnancy. If you have an active eating disorder or a history of eating disorders, please speak to your midwife or obstetrician about any specialist help you may need.

What should I eat in the third trimester?

By the third trimester, you may know that eating for two is a myth and that you only need about 200 calories extra per day at this stage. If you are expecting twins or triplets you may need more than 200 calories to support the extra energy demands of growing multiple babies. Ensuring you are eating enough calories will help to support your energy levels, which you might find are low at the moment. It can be fun to remember that your baby’s taste buds are developed enough to work by month seven, and he or she is tasting what you eat through the amniotic fluid that surrounds them, which can have influence on their taste preferences when weaning.

Calcium is essential for bone development during this trimester. Your baby’s bones are hardening (apart from those in their skull, which stays soft so the head can be birthed safely while protecting the brain). Calcium can be found in dairy foods, sardines, kale, oranges or fortified foods such as breads or cereals. If you drink non-dairy milks such as oat, almond or soya you should choose one that is fortified with calcium.

Which other foods can I enjoy while supporting my baby?

Other than energy requirements increasing in your last trimester it is also important to aim for a nutrient dense diet during your pregnancy, as your requirements for protein and some micronutrients such as riboflavin (B2) and Vitamin C also increase. Aim to include whole grain carbohydrates, proteins and vegetables/salads with every meal as well as including 2-3 portions of fruit throughout the day. Including healthy unsaturated fats is important to support your baby's brain development, as well as hormone production. Avocados, nuts, seeds, olives and salmon are all good sources of unsaturated fats. Beyond this, you should aim to avoid alcohol completely and restrict caffeine to no more than 200mg a day.

What should I avoid consuming in the third trimester?

The same guidelines apply regarding food safety throughout your pregnancy. There is no internationally recognised guideline for food safety during pregnancy, so please ask your healthcare team about foods you’re uncertain of.

There's a small chance that unpasteurised or soft-ripened dairy products such as brie or camembert may contain a bacteria called listeria. In rare cases this can cause an infection called listeriosis. Listeriosis can lead to miscarriage or stillbirth or make your newborn baby very unwell. To reduce the risk of this bacteria being present you can cook unpasteurised cheeses until it's steaming hot.
Carpaccio, steak tartare, and unwashed fruits and vegetables pose a toxoplasmosis risk to pregnant women. Cured meats like chorizo and salami can also be a risk if you’re not sure of the preparation process. Traditionally, these meats are fermented and cured rather than cooked. To be safe, this type of meat should be fully cooked, and make sure fruits and vegetables are clean.

In the UK, you can eat eggs raw or partially cooked if they have the Red Lion stamp or are hen’s eggs produced under the Laid in Britain scheme. All other eggs should be fully cooked to avoid the risk of salmonella.

Raw fish and shellfish should be avoided due to the potential presence of bacteria or parasites. Cooked fish is safe to eat and it’s recommended to eat 1-2 portions of oily fish such as salmon, mackerel, anchovies, sardines or herring per week. These fish contain an essential fatty acid called Omega 3, which is essential for the development of the baby's brain and eyes in the third trimester. Unfortunately, tuna does not count as an oily fish and due to the high mercury content should be limited to two tuna steaks or four medium-size cans of fish a week. Other high mercury fish include shark, swordfish, king mackerel, or tilefish.

Try to limit ultra processed carbohydrates that are high in fat and sugar as they provide little nutritional benefit. Including foods such as crisps and biscuits won’t harm your baby but it’s important tobe mindful of how often and how much you are eating. Overindulging in these foods may result in less nutrient dense foods being eaten and compromise overall nutritional intake and also not sustain your energy levels.

Remember that chocolate contributes to your caffeine intake. As a rule, the higher the cocoa content of a bar, the higher the caffeine content. White chocolate contains no caffeine.

What if I can’t face eating?

As we learned from Dr. Shree in Episode 2 of Unii’s Antenatal Journey, the weight and size of your uterus in the third trimester, as well as hormonal changes, can cause heartburn, constipation, and bloating. Many women don’t feel like eating when their digestive system is sluggish, and making “little and often” your goal can help. You should not be losing weight at this stage in your pregnancy, so keep an eye on the scale if you’ve been eating more lightly, as you won’t usually be weighed at antenatal checks. Staying hydrated with water and uncaffeinated drinks is also important. Remember that water is circulating nutrients around the body as well as helping you remove waste. You may find it helpful to avoid drinking large volumes of fluids alongside your meals and to sip on fluids throughout the day as this can worsen heartburn.

What can I do to reduce my constipation?

Ensuring enough fibre from different sources can help to keep things moving. Try to include foods like kiwis, oats and chia seeds in your diet along with keeping hydrated and regular physical activity. If these changes are insufficient to bring relief, then you may be recommended to take medication such as laxatives.

What if I’m vomiting again?

First-trimester nausea and vomiting can return (or occur for the first time) in the final weeks of pregnancy. This is thought to be hormone-related, and the stomach acid can be hard on your tooth enamel. Rinse your mouth with plain water after each time you are sick. This will help prevent the acid in your vomit from damaging your teeth. Do not brush your teeth straight away, as they will be softened by the acid from your stomach. Wait about an hour before brushing. Eating dry toast, staying hydrated, and getting plenty of rest can help when you’re feeling sick. Severe nausea and vomiting in this trimester can be a symptom of some serious conditions as well as an early sign of labour. Always check in with your midwife or doctor. Antiemetics, like Xonvea which is a newly licensed antiemetic in the UK, are not known to have any side effects in babies so even if it isn’t labour, there’s no need to suffer through it. Ginger is often mentioned for pregnancy sickness and some find it may help with very mild nausea but is unlikely to reduce moderate to severe nausea or sickness.

Should I still be taking my prenatal vitamins?

Hopefully you would have taken folic acid throughout your first trimester. Throughout the rest of your pregnancy women in the UK should be taking 10-25mcg of Vitamin D daily during their pregnancy and continuing this if going on to breastfeed. Depending on your dietary intake whether you choose to omit any food groups if you are vegan, vegetarian, pescetarian etc., you may consider taking a prenatal multivitamin throughout your pregnancy. Consistently consuming a well-balanced diet can be difficult for some women when keeping up with working life or looking after other children so many find a prenatal multivitamin helpful to meet their nutritional needs. Always check that your multivitamin is suitable for pregnancy, for example you should avoid Vitamin A, which can be harmful to the development of your baby.

If I need to eat regularly during pregnancy, when do I take my iron supplements?

Iron deficiency anaemia is very common in pregnancy due to the extra demand for red blood cells. Your iron levels will be monitored during routine blood tests and iron supplements recommended if anaemia is identified.

The best time to take your iron supplements is on an empty stomach ideally an hour before food and 2 hours after eating. Iron supplements can cause constipation, so alongside your supplement remember to keep hydrated and include plenty of fibre in your diet. There are several types of iron supplements. If you find you don’t tolerate the initial one your health care provider prescribes you may want to trial another. You may also be recommended alternate day iron supplements which have been found to be just as effective at raising your iron levels and cause fewer side effects.

Having vitamin C alongside your iron supplement can help the absorption so including foods such as oranges / orange juice, kiwi, sweet potato or red bell peppers can be helpful. Tea, coffee and calcium can inhibit the absorption of iron so avoid taking these with your iron supplement.

What should I eat in the third trimester?

Nutrition is a top priority. Here's Unii's advice.