39 weeks pregnant

Third trimester about 8 months

At 39 weeks pregnant, your baby is about the size of a small watermelon.

Baby this week

Watercolor illustration for week 39: Size of a small watermelon

About 50cm. The baby is fully developed and ready for birth. The skull bones are still slightly separate to allow them to compress during delivery. The baby could be born any moment.

Did you know? The ideal birth window is 39–40 weeks — research shows babies born at 39 weeks have fewer complications than those born at 37–38 weeks, even though all are technically full term.

What she may be feeling

Tips for her this week

For partners

Partner to-do list

How to support your partner in the third trimester

This week together

When to call your doctor or midwife

Contact your care provider right away, or call emergency services, if she has:

Trusted guidance: NHS: Pregnancy · NHS: Pregnancy complications · ACOG: Pregnancy · Pregnancy Info: Your pregnancy

Common questions

How big is the baby at 39 weeks?

At 39 weeks pregnant, your baby is about the size of a small watermelon. About 50cm.

How many months is 39 weeks pregnant?

39 weeks pregnant is about 8 months, in the third trimester.

What can partners do at 39 weeks?

This is the ideal birth window. Be present, be calm, be available. If labor doesn't start this week, don't panic — due dates are estimates, not deadlines.

All weeks · The partner's guide to pregnancy