Third Trimester

Week 39

Your baby is the size of a Mini watermelon

Baby Size

Mini watermelon

Length

14.4 in (36.5 cm)

Weight

5.9 lb (2.65 kg)

Trimester

Third Trimester

Your Baby at Week 39

Full-term! Your baby is the size of a mini watermelon and ready for birth. The brain is still developing rapidly and will continue to grow after birth.

Key milestone: Your baby is full-term! The brain continues developing rapidly. The baby can focus their eyes and track light.

Your Symptoms

Impending labor signs. Increased pelvic pressure. Diarrhea or loose stools (hormonal). Cervix may begin dilating.

Tip for This Week

You're full-term! Any day now. Try relaxation techniques, gentle walking, and rest.

Your Body at Week 39

In the third trimester, your growing uterus presses against your diaphragm, stomach, and bladder. Shortness of breath, heartburn, and frequent urination are common. Your body is producing relaxin, a hormone that loosens joints and ligaments to prepare for birth.

Your baby at week 39 is the size of a Mini watermelon, measuring about 14.4 in (36.5 cm) and weighing roughly 5.9 lb (2.65 kg). Every kick, roll, and hiccup is a sign that your baby is growing strong. Soon you'll hold them in your arms.

Your Baby's Development This Week

Full-term! Your baby is the size of a mini watermelon and ready for birth. The brain is still developing rapidly and will continue to grow after birth. The key milestone this week is that your baby is full-term! the brain continues developing rapidly. the baby can focus their eyes and track light.

The third trimester is about preparation — your baby is practicing breathing, sucking, and swallowing for life outside the womb. Each week of this stage significantly improves their chances of a healthy start. The countdown to meeting your baby has begun.

This week's voice theme

Full-term and fabulous — my first hello is almost here.

Imagine hearing this every morning — a voice note from your baby that evolves week by week.

Hear your baby's voice →

Frequently Asked Questions

What is the difference between full-term and early-term?

Full-term is 39-40 weeks. Babies born at full-term have the best health outcomes with fully mature lungs and brains.

How can I naturally induce labor?

Gentle walking, sex (prostaglandins in semen can help), nipple stimulation, and acupressure may help. Always consult your provider.