Week 30: The Brain Is Growing Fast

Your baby's brain is in an intense period of growth! The surface is becoming more and more folded, creating room for billions of nerve connections. Your baby now weighs around 1.3–1.5 kilograms and measures approximately 40 cm from head to heel — the size of a large cucumber.

The bone marrow has taken over production of red blood cells, the eyes can focus, and your baby is increasingly ready for life on the outside. There are only 10 weeks left until your due date!

With just 10 weeks to go, it is time to get serious about preparations. Many people experience stronger pregnancy symptoms now, but there is good support available — from your midwife, a physiotherapist, and through self-care.

Baby's Development

Brain growth: The brain is growing rapidly and the surface is becoming more wrinkled. The characteristic folds (gyri and sulci) create room for more nerve cells and connections
Temperature control: The brain can now better control body temperature than before
Blood cells: The bone marrow has taken over production of red blood cells from the liver — an important maturation step
Lanugo disappearing: The fine body hair that has covered the baby is beginning to disappear
Vision: The eyes can focus, and the baby follows light sources through the belly. Pupils react to light
Lung maturation: Surfactant is being produced in increasing amounts — essential for the lungs to function after birth
Weight and length: Your baby weighs around 1.3–1.5 kg and measures about 40 cm from head to heel
Taste and smell: The baby can taste differences in the amniotic fluid based on what you eat, and flavor preferences are already beginning to form

Brain Development in Detail

At week 30, the brain is growing by several grams per week. The characteristic folds in the brain surface dramatically increase the surface area — a smooth brain would be far less efficient. Each fold creates room for billions of nerve connections (synapses) that are the foundation for all thinking, learning, memory, and sensory experience.

Omega-3 fatty acids, especially DHA, are building blocks for brain cell membranes and are therefore especially important now. WHO and ACOG recommend that pregnant women eat fish 2–3 times per week, with at least one serving being a fatty fish like salmon or mackerel. DHA supplements may be relevant if you do not eat fish.

Your Body

Shortness of breath: The growing uterus is pressing against the diaphragm and making breathing feel tighter. This is completely normal and improves when the baby descends toward the end
Mood swings: Hormones, fatigue, and thoughts about birth can cause emotional swings
Nesting instinct: Many pregnant women suddenly feel the urge to clean, tidy, and get everything ready for the baby
Back pain: The growing belly puts extra strain on the lower back
Sleep difficulties: It is hard to find a comfortable position, and you wake up more often at night
Pelvic pain: The hormone relaxin loosens the joints, which can cause pain in the pelvis and pubic symphysis
Braxton Hicks: Practice contractions are becoming more noticeable. The uterus tightens for 20–30 seconds and then relaxes again
Swelling: Mild swelling in the legs and feet is common, especially toward the end of the day

Braxton Hicks vs. Real Labor

Braxton Hicks (practice contractions) become more common from around week 28–30. Here is how to tell them apart from real labor:

Braxton Hicks:

Irregular and unpredictable
Go away with rest or a change of position
Felt mostly at the front of the belly
Do not get stronger over time

Real Labor:

Regular and getting more frequent
Get stronger over time
Felt in the back and radiate forward
Do not go away with rest

If you are unsure, contact your labor and delivery unit — they are happy to help you assess. A contraction timer app can help you keep track of the intervals.

Good to Know

The nesting instinct is a real phenomenon that many people experience in the third trimester. It is wonderful to prepare the home, but remember not to overexert yourself. Ask for help with heavy lifting and take breaks. Your back can handle less than usual now.

Good posture makes a big difference for your back. Wear shoes with good support, and avoid standing in one position for too long. Swimming is wonderful now because the water supports your body and relieves pain. Prenatal yoga can also help with posture, pain relief, and mental preparation for birth.

Your baby is growing most in the final weeks, and you need around 300 extra calories per day in the third trimester according to WHO and ACOG. Choose nutritious food such as whole grains, vegetables, and lean proteins. Omega-3 from fish is important for brain development — WHO recommends 2–3 portions of fish per week, with at least one being a fatty fish like salmon or mackerel.

Sleep can be challenging now. Try sleeping on your left side with a pillow between your knees and under your belly. This position gives the best blood flow to the baby and relieves the back. Avoid lying flat on your back for extended periods, as the uterus can press on the vena cava (a major blood vessel) and cause dizziness.

Preparing for Birth

With 10 weeks left, it is time to prepare:

Birth Preparation Classes

Many hospitals and birth centers offer classes between weeks 28 and 36. Classes typically cover:

The phases of labor and what to expect
Breathing techniques and pain relief
The partner's role during birth
Breastfeeding and the first days with the baby
A tour of the maternity unit

Your Birth Plan

Now is a good time to create a birth plan or birth preferences document — your personal record of your wishes and preferences for the birth. Include:

Preferred pain relief (epidural, gas and air, water, natural)
Who you want present
Music and lighting preferences
Skin-to-skin contact after birth
Breastfeeding in the first hour

Hospital Bag

Start packing your hospital bag — you should have it ready from week 36:

Clothes for you and the baby
Toiletries and comfort items
Documents and maternity records
Snacks and drinks
Phone charger and camera

The Nursery

Check that everything you need is in place:

Crib with an approved mattress
Changing table or changing mat
Storage for clothes
Night light and room thermometer

Prenatal Checkups in the Third Trimester

From week 28, prenatal appointments become more frequent:

Weeks 28–36: Checkup every 2 weeks
Weeks 36–40: Checkup every week
At each checkup: Blood pressure, urine, weight, fundal height, baby's position, and heartbeat

Important Tests

Glucose tolerance test: If not done earlier, screening for gestational diabetes
Anti-D injection: If you are Rh-negative, given at week 28
GBS screening: Testing for Group B Streptococcus may be offered around week 35–37 depending on your local guidelines
Hemoglobin: Iron levels checked regularly, with supplements recommended as needed

Choosing a Birth Setting

Around weeks 28–32 is a good time to confirm your birth setting. Options typically include:

Hospital maternity unit: For all pregnant women, including higher-risk pregnancies
Midwife-led unit or birth center: For healthy women with uncomplicated pregnancies
Home birth: With a qualified midwife, for healthy women with normal pregnancies

Talk to your midwife about what is right for you. Make sure to register at your preferred birth setting in good time.

Pelvic Girdle Pain and Relief

Pelvic girdle pain affects up to 20 percent of pregnant women, according to research:

Symptoms

Pain at the front of the pelvis (pubic symphysis)
Pain in the lower back or sacroiliac joints
Pain radiating into the groin or thighs
Worst when walking, climbing stairs, or turning in bed

What Helps

Pelvic support belt: Stabilizes the pelvis and reduces pain
Physiotherapy: Can be very effective — ask your midwife for a referral
Swimming: Takes pressure completely off the body
Avoid wide steps: Keep your legs together when turning in bed
Pelvic floor exercises: Strengthens the muscles that support the pelvis
Pain relief: Paracetamol (acetaminophen) is generally considered safe during pregnancy — check with your doctor
Acupuncture: Some find relief from acupuncture — ask your midwife about options in your area

Exercise in the Third Trimester

It is still recommended to exercise in the third trimester, according to WHO and ACOG. Regular movement helps with many common complaints such as back pain, swelling, and sleep problems. Adjust your activity level to how you feel.

Good Activities Now

Swimming: Wonderful in the third trimester — the water supports your body and gives a feeling of weightlessness. Many pregnant women experience significant pain relief in the water
Walking: Short walks at a moderate pace keep your body moving. Wear good supportive shoes
Prenatal yoga: Strengthens your body, provides relaxation, and prepares you mentally for birth. Focus on breathing exercises and hip-opening poses
Pelvic floor exercises: Especially important now. A strong pelvic floor helps during birth and speeds up recovery afterward
Light strength training: With a focus on posture and back strength

Exercise to Avoid

Activities with a risk of falling
Heavy lifting (over 10–12 kg)
Exercises on your back (after week 28, the uterus can press on the vena cava)
Intense exercise that causes breathlessness
Contact sports

Nutrition in the Third Trimester

You need about 300 extra calories per day in the third trimester, according to WHO and ACOG. The quality of food is more important than the quantity.

Key Nutrients Now

Iron: Your baby is building up iron stores. Good sources: red meat, beans, lentils, dark leafy greens. Combine with vitamin C for better absorption
Calcium: Important for the baby's bone development. Dairy products, green vegetables, and calcium-fortified products
Omega-3 (DHA): Critical for brain development. WHO recommends 2–3 portions of fish per week
Protein: Increased need to support the baby's growth. Meat, fish, eggs, beans, and dairy products
Fiber: Prevents constipation. Whole grains, fruit, vegetables, and legumes
Water: At least 2 liters daily — helps with constipation and swelling

Iron Deficiency

Iron deficiency is very common in the third trimester. Symptoms may include:

Unusual fatigue and weakness
Dizziness
Pallor
Heart palpitations
Difficulty concentrating

Your midwife checks hemoglobin levels at appointments and will recommend iron supplements if needed. Take iron supplements between meals with a glass of orange juice for the best absorption.

Sleep in the Third Trimester

Sleep problems are common in the third trimester. Prioritizing rest is important, even if sleep quality is poorer than usual.

Tips for Better Sleep

Side sleeping: Sleep on your left side with a pillow between your knees and under your belly
Consistent routine: Go to bed and wake up at the same time
Avoid screens: Put away your phone and tablet 30 minutes before bed
Reduce evening fluids: Drink most of your fluids during the day to reduce nighttime bathroom visits
Relaxation: Try deep breathing, progressive muscle relaxation, or meditation
Temperature: Keep the bedroom cool and well ventilated

Why the Left Side?

Sleeping on your left side gives the best blood flow to the placenta and baby. It also relieves the vena cava (a major blood vessel) and can reduce swelling in the legs. Don't stress if you wake up on your back — just roll over and go back to sleep.

For Your Partner

Make preparations a shared activity — set up the nursery or sort baby clothes together
Be patient with mood swings — a listening ear means a great deal
Plan something enjoyable together — a movie night, dinner out, or a spa evening at home
Help find a good physiotherapist if pelvic pain is a problem
Join birth preparation classes together
Discuss birth plans and wishes — create your birth preferences document together

Tips for Week 30

Swim or take walks: Swimming relieves the back, and walking keeps your body moving
Pelvic floor exercises: Daily exercises prepare you for birth. Try 3 sets of 10 repetitions
Book a birth class: Many classes fill up quickly. Start thinking about your birth preferences too
Eat omega-3: Salmon and mackerel provide important fatty acids for your baby's brain development
Prenatal yoga: Gentle exercises that strengthen the body and bring relaxation — perfect for the third trimester
Start on the hospital bag: Begin gathering items you will need
Follow your pregnancy calendar: Keep up with what is happening week by week in these final months

When to Contact a Doctor

Contact your doctor or midwife if you experience:

Severe pelvic pain that makes it difficult to walk or turn over
Numbness or tingling in the legs that does not ease
Sudden severe swelling in the face or hands (could indicate preeclampsia)
Persistent headache with vision disturbances
Regular contractions that do not stop with rest
A sudden reduction in fetal movements
Leaking fluid from the vagina (could be amniotic fluid)

After week 28, you should act on changes in your baby's movement pattern. Contact your labor and delivery unit if you notice that the baby is moving noticeably less than usual. It is always better to check once too many times than once too few.

Preeclampsia can develop in the third trimester. Symptoms include high blood pressure, protein in the urine, headache, vision disturbances, and swelling. Seek help promptly if you suspect preeclampsia.

Did You Know?

Your baby's brain is growing so fast now that it increases by several grams per week. The surface is becoming more and more folded, allowing the brain to contain billions of nerve connections
Lanugo — the fine body hair that has covered the baby — is beginning to disappear now. Some may still be present at birth, especially on the shoulders and back
The bone marrow has now taken over production of red blood cells from the liver. This is an important maturation step showing that the body is ready for life outside the womb
Your baby can now focus its gaze and follow light sources through the abdominal wall. The pupils react to light by contracting
Vision is the least developed sense at birth — newborns see best at 20–30 cm distance, exactly the distance between a mother's breast and face during feeding

Common Questions About Week 30

What is the nesting instinct?

The nesting instinct is a well-known phenomenon where pregnant women suddenly feel a strong urge to clean, tidy, and get everything ready for the baby. It can arrive as a sudden burst of energy in the middle of fatigue. Enjoy the motivation, but be careful not to overexert yourself — ask for help with heavy lifting and take breaks!

Is pelvic pain normal at week 30?

Yes, pelvic girdle pain is common and affects up to 20 percent of pregnant women. It is caused by the hormone relaxin loosening the joints to prepare the body for birth. Pain can be felt at the pubic symphysis, in the lower back, or in the groin. A pelvic support belt, physiotherapy, and avoiding wide steps can help. Ask your midwife for a referral to a physiotherapist.

How many extra calories do I need in the third trimester?

In the third trimester, your body needs about 300 extra calories per day, according to WHO and ACOG. That is roughly equivalent to an extra snack — for example, a couple of slices of bread with a topping, or a bowl of yogurt with fruit and nuts. The quality of food is more important than the quantity — choose nutritious food with whole grains, proteins, and vegetables.

Is it normal to have mood swings in the third trimester?

Yes, hormones, fatigue, sleep problems, and thoughts about the approaching birth can all contribute to mood swings that are more pronounced than usual. This is completely normal and will stabilize after birth. Talk to someone you trust about how you are feeling, and raise it with your midwife if you feel low for an extended period. Prenatal depression can start during pregnancy.

What are Braxton Hicks contractions?

Braxton Hicks are practice contractions where the uterus tightens for 20–30 seconds and then relaxes. They are irregular, not painful (just uncomfortable), and go away with rest or a change of position. They prepare the uterus for birth. Contact your labor and delivery unit if contractions become regular, more frequent, or stronger — it could indicate preterm labor.

When should I have my hospital bag packed and ready?

Most recommendations are to have the hospital bag packed and ready from week 36. But there is no harm in starting to gather items from week 30. Have it standing by the door or in the car from week 36.

Next week: All five senses are active — your baby is experiencing the world!