Third Trimester Nutrition Guide
Final stretch nutrition for you and baby's preparation for birth
Overview
You're in the home stretch! The third trimester brings exciting anticipation as you prepare to meet your baby. During weeks 28-40, your baby will gain most of their birth weight, develop fat stores for temperature regulation, and their brain will undergo rapid development.
As your baby grows, you may experience increased discomfort, heartburn, and shortness of breath as your uterus expands. Eating smaller, frequent meals of nutrient-dense foods will help you manage symptoms while meeting your baby's nutritional needs.
Your nutritional focus shifts to preparing for labor, building iron stores for delivery, supporting baby's brain development, and potentially preparing your body for breastfeeding.
🔥 Increased Calorie & Nutrient Needs
Calories: +450-500 per day
Slightly higher than second trimester as baby gains about ½ pound per week. This equals a substantial snack like whole grain toast with avocado, egg, and a glass of milk.
Protein: 75-100g daily
Essential for baby's rapid weight gain and continued organ development. Also builds your strength for labor and delivery.
Iron: Extra important now
Baby is building iron stores for first 6 months of life. You need iron reserves for blood loss during delivery. Many providers check iron levels and prescribe supplements if needed.
⭐ Critical Nutrients for Third Trimester
Iron (27-30mg daily)
Top priority in third trimester. Baby is storing iron for first 6 months of life. You need reserves for blood loss during delivery (average 500mL). Low iron causes fatigue and increases complications.
Sources: Red meat (best absorbed), poultry, fortified cereals, lentils, spinach, pumpkin seeds
Pro tip: Take iron supplement with vitamin C (orange juice) for better absorption. Avoid calcium supplements at same time as they compete for absorption.
Omega-3 DHA (200-300mg daily)
Baby's brain triples in size during third trimester! DHA is crucial for neural development, vision, and cognitive function. Also supports your mental health postpartum.
Sources: Salmon (2-3 times/week), sardines, DHA-fortified eggs, walnuts, algae-based DHA supplements
Calcium (1000mg daily)
Baby's bones continue hardening and teeth are developing beneath gums. Calcium also helps prevent pregnancy-induced hypertension and preeclampsia.
Sources: Dairy products, fortified plant milk, sardines, kale, almonds, fortified orange juice
Vitamin K (90 mcg daily)
Important for blood clotting during and after delivery. Helps prevent excessive bleeding. Baby also needs vitamin K stores (they'll receive a vitamin K shot at birth).
Sources: Leafy greens (kale, spinach, collards), broccoli, Brussels sprouts, cabbage
Vitamin C (85mg daily)
Helps iron absorption (critical now), supports immune function, aids tissue repair, and strengthens blood vessels.
Sources: Citrus fruits, strawberries, bell peppers, broccoli, tomatoes, kiwi
Fiber (25-35g daily)
Prevents constipation which worsens as baby presses on intestines. Helps manage blood sugar and keeps you full.
Sources: Whole grains, fruits, vegetables, beans, lentils, oats, chia seeds
🥙 Power Foods for Third Trimester
Iron-Rich Power Foods
- •Lean red meat: 3oz provides ~3mg iron (best absorbed form)
- •Fortified cereals: Some provide 100% daily iron
- •Lentils & beans: 1 cup provides 6mg iron + protein + fiber
- •Spinach: Pair with vitamin C for better absorption
- •Pumpkin seeds: Great iron-rich snack
Brain Development Foods
- •Salmon: 3oz provides 1000mg DHA (wild caught preferred)
- •Sardines: Omega-3 + calcium + protein
- •Walnuts: Plant-based omega-3, easy snack
- •DHA eggs: Fortified with omega-3
- •Chia/flax seeds: Add to yogurt or smoothies
Energy-Sustaining Foods
- •Complex carbs: Quinoa, brown rice, oats (steady energy)
- •Lean proteins: Chicken, turkey, eggs (sustained fullness)
- •Nuts & nut butters: Healthy fats + protein
- •Greek yogurt: Protein + probiotics
- •Hummus with veggies: Protein + fiber combo
Labor Preparation Foods
- •Dates: Studies show 6/day from week 36 may ease labor
- •Red raspberry leaf tea: May tone uterus (ask provider)
- •Protein-rich foods: Build stamina for labor
- •Iron-rich foods: Prevent fatigue during labor
- •Hydrating foods: Watermelon, cucumber, berries
😌 Eating Strategies for Common Third Trimester Issues
Heartburn & Acid Reflux
Why it happens: Growing uterus pushes stomach acid up, progesterone relaxes esophageal sphincter
- • Eat 5-6 small meals instead of 3 large ones
- • Avoid lying down for 2-3 hours after eating
- • Skip spicy, greasy, acidic foods (tomatoes, citrus, chocolate)
- • Try bland proteins, complex carbs, non-citrus fruits
- • Sleep with head elevated on pillows
- • Drink milk or eat almonds to neutralize acid
Constipation
Why it happens: Progesterone slows digestion, baby presses on intestines, iron supplements
- • Increase fiber to 25-35g daily (whole grains, fruits, veggies, beans)
- • Drink 10-12 glasses of water daily
- • Try prunes or prune juice daily
- • Eat kiwi fruit (natural laxative)
- • Stay active - walk 30 minutes daily
- • Talk to doctor about switching iron supplement if severe
Swelling (Edema)
Why it happens: Increased blood volume, pressure on veins from uterus
- • Drink MORE water (helps flush excess sodium)
- • Limit salt intake but don't eliminate completely
- • Eat potassium-rich foods: bananas, sweet potatoes, avocados
- • Avoid processed foods high in sodium
- • Elevate feet when resting
- • Contact doctor if swelling is sudden or severe (could indicate preeclampsia)
Fatigue
Why it happens: Carrying extra weight, disrupted sleep, iron deficiency
- • Eat iron-rich foods with vitamin C for energy
- • Choose complex carbs over simple sugars for sustained energy
- • Include protein at every meal and snack
- • Avoid sugar crashes - skip sweets and refined carbs
- • Stay hydrated - dehydration causes fatigue
- • Consider asking doctor to check iron levels
Shortness of Breath
Why it happens: Uterus pushes on diaphragm, increased oxygen needs
- • Eat smaller, more frequent meals so stomach doesn't press on diaphragm
- • Avoid large meals that make you feel overly full
- • Sit upright while eating to give lungs more room
- • Eat slowly and chew thoroughly
💪 Nutrition to Prepare for Labor
Build Your Iron Stores (Weeks 28-40)
You'll lose 500mL of blood during vaginal delivery (up to 1000mL for C-section). Good iron stores prevent postpartum anemia and exhaustion.
Action: Eat iron-rich foods daily. Take prenatal vitamin. Ask doctor to check iron levels at 28 weeks.
Eat Dates Daily (Weeks 36-40)
Research suggests eating 6 dates per day in the final month may reduce need for induction and shorten early labor. Dates are also high in natural sugars for energy.
Action: Eat 6 Medjool dates daily starting at 36 weeks. Add to smoothies or eat as a sweet snack.
Stay Hydrated (All Third Trimester)
Dehydration can trigger Braxton Hicks contractions and may contribute to early labor. Proper hydration keeps amniotic fluid levels healthy and helps prevent constipation.
Action: Drink 10-12 glasses (80-96oz) of water daily. More if exercising or in hot weather.
Pack Labor Snacks (Week 37+)
Many hospitals allow light snacks in early labor. Having easy-to-digest, energy-boosting foods can help sustain you.
Ideas: Honey sticks, dates, granola bars, crackers, lollipops, coconut water, juice boxes
🍽️ Sample Third Trimester Day
Breakfast (8am)
Fortified oatmeal with walnuts, blueberries, flax seeds, drizzle of maple syrup
Nutrients: Iron, omega-3, fiber, calcium (if made with milk)
Mid-Morning Snack (10:30am)
Greek yogurt with granola and strawberries
Nutrients: Protein, calcium, vitamin C, probiotics
Lunch (1pm)
Lentil soup with whole grain bread, side salad with olive oil dressing
Nutrients: Iron, protein, fiber, healthy fats
Afternoon Snack (4pm)
6 Medjool dates with almond butter, glass of milk
Nutrients: Natural sugars, calcium, protein (labor prep!)
Dinner (6:30pm)
Grilled salmon, quinoa, roasted Brussels sprouts with garlic
Nutrients: Omega-3 DHA, protein, vitamin K, iron
Evening Snack (9pm)
Whole grain crackers with cheese, handful of pumpkin seeds
Nutrients: Calcium, protein, iron, magnesium
🤱 Nutrition for Breastfeeding Preparation
If you plan to breastfeed, your nutritional needs will actually be higher postpartum than during pregnancy. Starting good habits now will help you transition smoothly.
Continue prenatal vitamins: You'll need them while breastfeeding too
Focus on omega-3: DHA transfers through breast milk for baby's brain development
Maintain protein intake: Breast milk production requires significant protein
Stay hydrated: You'll need even more fluids when your milk comes in (3-5 days postpartum)