Pregnancy Nutrition: What to Eat Each Trimester

What you eat during pregnancy directly impacts your baby's development and your own health. But pregnancy nutrition doesn't have to be complicated. This evidence-based guide breaks down what matters most each trimester, which supplements are essential, and how to manage the nutritional challenges that come with morning sickness, food aversions, and heartburn.

Prenatal Supplements: Start Before You're Pregnant

The neural tube closes in the first 28 days of pregnancy — often before you even know you're pregnant. This is why folic acid supplementation should start before conception.

• Folic acid: 400–800 mcg daily (start before conception, continue through first trimester)
• Iron: 27 mg daily (your needs nearly double in pregnancy)
• Calcium: 1,000 mg daily
• Vitamin D: 600 IU daily (many OBs recommend 1,000–2,000 IU)
• DHA/Omega-3: 200–300 mg daily for brain development
• Iodine: 220 mcg daily (critical for thyroid and brain development)

First Trimester (Weeks 1–12): Surviving Morning Sickness

The first trimester is when nausea and food aversions peak. Your caloric needs haven't increased yet (you're not "eating for two" in terms of calories), but nutrient quality matters enormously.

• Focus on folate-rich foods: leafy greens, legumes, fortified cereals
• Eat small, frequent meals to manage nausea
• Cold foods often cause less nausea than hot foods
• Ginger (tea, candies, capsules) is evidence-based for nausea relief
• If you can only tolerate bland foods, that's okay — your prenatal vitamin covers the gaps
• Stay hydrated — dehydration worsens nausea

Second Trimester (Weeks 13–26): Building Baby's Bones and Brain

The second trimester is typically when appetite returns and energy improves. You need approximately 340 extra calories per day.

• Calcium-rich foods: dairy, fortified plant milks, sardines, leafy greens
• Iron-rich foods: lean red meat, poultry, fish, legumes, fortified cereals
• Pair iron-rich foods with vitamin C to enhance absorption
• DHA sources: fatty fish (salmon, sardines, trout) 2–3 times per week
• Protein: aim for 70–100g daily — eggs, meat, fish, legumes, dairy

Third Trimester (Weeks 27–40): Fueling Growth and Preparing for Birth

Baby is growing rapidly and your caloric needs increase to approximately 450 extra calories per day. Heartburn and reduced stomach capacity are common challenges.

• Eat smaller, more frequent meals to manage heartburn and fullness
• Continue iron-rich foods — anemia risk increases in the third trimester
• Vitamin K (leafy greens) supports blood clotting for delivery
• Magnesium (nuts, seeds, whole grains) may help with leg cramps
• Stay well-hydrated — dehydration can trigger Braxton Hicks contractions

Foods to Avoid During Pregnancy

• Raw or undercooked meat, poultry, and seafood (listeria, salmonella risk)
• High-mercury fish: shark, swordfish, king mackerel, tilefish, bigeye tuna
• Unpasteurized dairy and juices
• Raw sprouts
• Deli meats and hot dogs (unless heated to steaming)
• Alcohol — no safe amount has been established
• Excess caffeine — limit to 200 mg/day (about one 12-oz coffee)