The Third Trimester: Nourishing your body for birth, baby and postpartum

The third trimester, from week 28 until birth, can feel very different from the second.

Your baby is gaining weight rapidly, the brain and lungs continue to

mature, and nutrients are being transferred and stored in preparation for life outside the womb.

At the same time, your own body is carrying more weight, sleep can become more difficult, digestion may feel slower, and your cardiovascular and metabolic systems are working hard to support both you and your baby.

For me, this trimester is not only about growing your baby, it is also about preparing your body for birth, recovery and the nutritional demands of postpartum.

1. Nutrition: what should you focus on?

You don't need a completely different diet in the third trimester. But there are a few nutrients I pay particular attention to.

Protein

Your baby is growing rapidly, while your own body continues to build and maintain maternal tissues. Try to include a meaningful source of protein at every meal while slightly increasing the quantity (from when you were not pregnant): eggs, fish, meat, poultry, Greek yoghurt, tofu, beans or lentils.

Iron

Iron requirements are high during pregnancy because of increased maternal red blood cell production and the needs of the developing baby. Iron deficiency also becomes more common as pregnancy progresses.

That's why it is important to know your iron status before birth. If haemoglobin or iron stores are low, food alone may not be enough and supplementation may be needed.

Anyway, including iron-rich foods regularly is a must during pregnancy and these are the foods you must make sure you are eating every day: meat, poultry, seafood, eggs, beans, lentils and leafy greens. Combine plant sources with vitamin C-rich foods such as kiwi, citrus fruit, berries or peppers to improve absorption.

DHA + choline

The third trimester is a particularly important period for fetal brain development, and DHA accumulates rapidly in the developing brain and retina during this period. Low-mercury oily fish such as salmon, sardines and trout provides DHA, while eggs are one of my favourite pregnancy foods for choline.

Choline needs reach around 450 mg/day during pregnancy, yet many women don't consume enough and many prenatal supplements contain little or none, so increase your food intake with choline and choose a prenatal with enough quantity of choline.

Calcium + vitamin D

Your baby's skeleton continues to mineralise during the third trimester.

This is why you should aim for calcium-rich foods every day: yoghurt, cheese, milk or fortified alternatives, sardines with bones, tofu prepared with calcium and green vegetables.

Vitamin D supports calcium metabolism and bone health, but dietary sources are limited, which is why supplementation may be appropriate depending on your prenatal, diet, individual status and local pregnancy recommendations.

2. What about supplements?

Supplements in the third trimester should be chosen with a little more intention than simply continuing the same prenatal throughout pregnancy. Your prenatal can help cover nutritional gaps, but it may not provide meaningful amounts of every nutrient that becomes relevant as birth approaches.

In my perspective, you can take:

• Iron: If proven by lab tests that your iron and/or ferritin levels as well as haemoglobin are low, then you must supplement. Remember that iron needs remain high, and low iron stores may contribute to fatigue and reduce your reserve for blood loss during birth.

• DHA and other omega-3 fats: DHA supports your baby's brain and eye development, particularly during the final trimester. Omega-3 fats also help support a balanced inflammatory response, which is relevant as your body prepares for labour and recovery. Choose a pregnancy-appropriate product that has been tested for contaminants.

• Magnesium: Magnesium is involved in muscle and nerve function, energy production and glucose metabolism. Some women find that adequate magnesium supports muscle relaxation (and it can help with cramps!), bowel regularity or sleep, although it is not a universal pregnancy supplement and should not be used to treat pregnancy complications without medical guidance. If your main issue is that your sleep is disturbed, then take magnesium glycinate; if your are feeling constipated then prefer to take magnesium citrate.

• Choline: Choline supports fetal brain development and nervous-system function, but it is often missing or present only in small amounts in prenatal supplements.

• Iodine and vitamin D: Both are important for thyroid function, bone development and immune regulation, but requirements vary depending on your diet, location, prenatal supplement and blood results. Avoid adding separate products without checking the total dose, especially if you are already taking a prenatal.

• Calcium: Calcium is important for your baby's skeleton and for your own bone health, but it is usually not included in meaningful amounts in a prenatal. Prioritise calcium-rich foods and discuss separate supplementation if your dietary intake is low or your healthcare professional recommends it. If you take calcium and iron, ask how to space them because calcium can reduce iron absorption.

The third trimester is also a good time to review supplements for tolerability and practicality. Constipation, nausea, reflux and poor sleep can all be worsened by the wrong product or timing. A supplement that looks comprehensive on paper is not useful if you cannot take it consistently.

Before adding anything, review your full list with a qualified professional. This is especially important with herbal products, high-dose antioxidants, magnesium, fish oil and any supplement marketed for labour preparation.

3. Keep moving (but adapt!)

Movement may look different now than it did at 20 weeks and that's okay.

Walking, pregnancy appropriate strength training, mobility work and gentle stretching can all help you maintain strength and mobility as your body changes.

At this stage, I particularly like maintaining strength in the legs, glutes, back and upper body, not only for pregnancy, but because you will soon spend a surprising amount of time lifting, carrying and feeding a baby.

Listen to your body and adapt intensity as your pregnancy progresses. Your obstetric or maternity team should advise you if you have a condition requiring modification or restriction of exercise.

4. Sleeping well may be more difficult now

A bigger abdomen, fetal movements, reflux, pelvic discomfort and frequent trips to the bathroom can make uninterrupted sleep increasingly difficult. You may not be able to control every awakening, but you can protect the conditions around your sleep.

Build or maintain an healthy sleep routine, by keeping evenings quieter. Reduce bright light and screens before bed when possible. Eat dinner early enough to reduce reflux. Use breastfeeding pillows to make your sleeping position comfortable. Get daylight in the morning and continue moving during the day.

If you don't sleep good enough throughout the night, try to rest during the day by making quick naps.

5. Stress management doesn't mean having a stress-free pregnancy

Preparing for birth can bring excitement, but also uncertainty. Will labour start naturally? Will the baby be okay? What will birth feel like? Will I be able to breastfeed? How will life change afterwards?

Your goal shouldn't be to eliminate those thoughts, it's to give your nervous system regular opportunities to come out of a state of constant activation.

That might mean walking outside, breathing slowly for a few minutes, prenatal yoga, talking openly with your partner, reducing unnecessary commitments or simply having periods of the day where nothing is expected from you.

If anxiety, low mood or distress is becoming persistent or difficult to manage, this deserves professional support rather than being dismissed as “normal pregnancy hormones.”

6. Start thinking beyond birth

One thing I wish we talked about more during pregnancy is the mother after the baby arrives.

• Before birth, think practically about how you will nourish yourself when you're tired and caring for a newborn. This is the time to fill the freezer and have easy protein-rich foods available.

• Organise help and know who can bring you meals.

• Discuss nighttime support with your partner.

• Understand what breastfeeding may demand from your body.

• Know your iron status, particularly if you've already struggled with low iron during pregnancy.

All of this is helped me a lot during the first weeks after birth, so I can't stress enough the need to focus on this as soon you enter the 3rd trimester. For my first baby, I didn't do it enough, but for the second one I invested on this and it was the best thing I could do for the "bien être" of my family.

Bringing it all together: What should you focus on during the third trimester?

Come back to the fundamentals:

• Eat regularly: Include protein at each meal, plenty of colourful vegetables and fruit, iron-rich foods, calcium-rich foods and healthy fats.

• Choose key nutrients: Continue your prenatal supplement and pay particular attention to iron, vitamin D, iodine, choline and DHA, depending on your individual needs and healthcare advice.

• Include low-mercury fish: Aim for 2–3 portions per week where possible, choosing options such as salmon, sardines or trout.

• Stay hydrated: Keep water nearby and drink regularly throughout the day.

• Keep moving: Walking, gentle strength training, mobility work and stretching can help you maintain strength and support your changing body. Adapt movement to how you feel.

• Prioritise rest and sleep: Sleep may be more difficult now, so create opportunities to rest during the day and protect a calming evening routine.

• Prepare for postpartum: Stock your freezer, organise practical support and plan easy, nourishing meals for the weeks after birth.

How I support women during pregnancy

Pregnancy care understandably focuses heavily on your baby's growth, scans, blood tests and preparing for a safe delivery. My work starts with a different question: how are you doing through all of this?

I look at your nutrition, nutrient status, energy, digestion, sleep, movement, stress, symptoms and supplements together rather than treating each one separately. We look at whether symptoms such as exhaustion, constipation or poor sleep have something modifiable behind them. Whether your iron and other relevant markers need attention. And how your daily routine can realistically support you without turning pregnancy into another list of things you have to do perfectly.

As birth gets closer, we don't stop at preparing for delivery. We prepare for the woman who comes home with the baby too.

Because my goal isn't simply to help you have a healthy pregnancy. It's to help you enter birth and postpartum well nourished, informed and with a plan for taking care of your body too.