Medical Disclaimer: This article is for informational purposes only. Always consult your healthcare provider.

Welcome to the third trimester! At 28 weeks, your baby is about the size of an eggplant—roughly 15 inches long and weighing about 2.2 pounds. This final stretch brings rapid growth, more frequent prenatal visits, and exciting preparation for your baby’s arrival. Your baby’s brain is developing complex thought patterns, and they may even be dreaming during REM sleep.

Baby Development at 28 Weeks

Your baby measures about 15 inches and weighs approximately 2.2 pounds. The brain is developing rapidly, with billions of neurons forming. Your baby now has REM sleep cycles, which may mean they’re dreaming. Eyes can blink and are sensitive to light.

Fat continues to accumulate under the skin, helping regulate temperature after birth. The lungs are maturing but not yet fully developed. Your baby’s immune system is strengthening with antibodies from you. For a complete overview, see our third trimester guide.

Your Body This Week

Prenatal visits increase to every 2 weeks from now until week 36. Your provider will monitor blood pressure, weight, fundal height, and baby’s position. You may receive the RhoGAM shot if Rh-negative and the Tdap vaccine (whooping cough protection for your baby).

Your belly is large and continuing to grow. You may experience shortness of breath, difficulty sleeping, and increased back pain. Braxton Hicks contractions may be more frequent.

Common Symptoms at 28 Weeks

Shortness of breath: Your uterus presses against your diaphragm. This improves when the baby “drops” near delivery.

Sciatica: Pressure on the sciatic nerve can cause shooting pain down your leg. Stretching and warm compresses help.

Frequent urination returns: The baby’s head is putting pressure on your bladder again.

Braxton Hicks contractions: More frequent practice contractions. Contact your provider if they become regular or painful.

What to Do This Week

Begin kick counts. Track your baby’s movements daily. You should feel at least 10 movements within 2 hours. See our baby movement guide.

Start planning your hospital bag.

Draft your birth plan.

Discuss the Tdap vaccine with your provider. It protects your newborn from whooping cough.

Continue safe exercise. See our guide.

Nutrition Spotlight: Third-Trimester Energy

You need about 450 extra calories daily in the third trimester. Focus on protein (for baby’s rapid growth), complex carbohydrates (for sustained energy), and healthy fats (for brain development). Continue adequate calcium, iron, and DHA. Visit our nutrition guide.

When to Call Your Doctor

  • Vaginal bleeding or fluid leaking
  • Regular contractions (more than 4-6 per hour before 37 weeks)
  • Severe headaches or vision changes
  • Sudden severe swelling
  • Fewer than 10 movements in 2 hours
  • Signs of preterm labor

See our when to call your doctor guide.

Frequently Asked Questions

How do I do kick counts?

Choose a time when your baby is usually active. Lie on your side and count movements. You should feel at least 10 in 2 hours. If you don’t, contact your provider.

What is the Tdap vaccine?

A vaccine given around 27-36 weeks that protects your newborn from whooping cough. Your antibodies pass to the baby, providing protection in their first months of life.

Is it normal to feel anxious about labor?

Very normal. Childbirth classes, talking with experienced parents, and discussing your birth plan with your provider can all help reduce anxiety.