40 Weeks Pregnant
At 40 weeks pregnant, your baby is about the size of a watermelon.
- Length
- 51 cm (20.1 in)
- Weight
- 3.4 kg (7 lb 8 oz)
- Trimester
- Third
- Month
- Month 9
- Weeks to go
- Due date week
Size of a watermelon
Your baby at 40 weeks
Happy due date week! The average newborn is about 51 cm long and weighs about 3.4 kg, the size of a watermelon. Only around 4 to 5 percent of babies arrive on their exact due date.
Your body at 40 weeks
If labor has not started, your provider will talk about monitoring and when to consider induction.
Common symptoms at 40 weeks pregnant
- Anticipation
- Pelvic pressure
- Contractions
- Fatigue
Every pregnancy is different. Having none of these symptoms is normal too.
Tips for week 40
- Ask your provider about your options if you go past your due date.
- Keep counting kicks; reduced movement always needs a call.
- Rest up and let others help.
Your week 40 checklist
- Ask about options if you go overdue
- Keep counting kicks
- Let others help
Helpful at 40 weeks
40 Weeks Pregnant: your questions answered
How big is a baby at 40 weeks pregnant?
At 40 weeks your baby is about the size of a watermelon: around 51 cm (20.1 in) long and weighing about 3.4 kg (7 lb 8 oz). Every baby grows at their own pace.
How many months is 40 weeks pregnant?
40 weeks pregnant is month 9 of your pregnancy, in the third trimester. This is your due date week.
What happens if I go past my due date?
Most babies arrive within two weeks of their due date. Your provider will offer extra monitoring and discuss induction, often between 41 and 42 weeks.
Sources
This guide is written from public guidance by the American College of Obstetricians and Gynecologists (ACOG), the NHS, the CDC and the World Health Organization. Baby sizes are averages; your baby may be bigger or smaller and still perfectly healthy.
General information only, not medical advice.
History of updates
- : Added a weekly checklist and common questions.
- : Matched fruit, length and weight to the Prego app.
- : Published.