Third Trimester

Pregnancy Week 40

Your baby is about the size of a watermelon 🍉due date!.

Week 39Week 40 / 40
🍉

Size comparison

Watermelon

Length

51.2 cm

Weight

3.5 kg

Milestone

Due date!

Baby's development at week 40

Your estimated due date has arrived! Only about 5% of babies are born on their due date, so stay patient. Your baby is perfectly ready — a fully formed human being waiting to meet you.

You've done it — 40 weeks of incredible work. Trust your body. Your baby will arrive when ready.

Common symptoms at week 40

NestingIrregular contractionsShow (blood-tinged mucus)Pelvic pressure

Eat more of

  • Calcium & Vitamin K (broccoli, kale)
  • DHA-rich fish (sardines, salmon — cooked)
  • Iron-rich foods to prevent anaemia
  • Fibre-rich foods to combat constipation
  • Small frequent meals to ease heartburn
  • Dates (studies suggest easier labour)

Foods to avoid

  • Alcohol
  • Gas-producing foods (beans, cabbage) if uncomfortable
  • Very spicy food if causing heartburn
  • Raw/undercooked meat
  • High-sodium processed food
  • Large meals that worsen reflux

Medically reviewed by First OPD Medical Team. Last reviewed on .

Based on average milestones from World Health Organization (WHO), ACOG, NHS UK. Educational only — not a substitute for personalised medical advice.

Track every week with a free First OPD account

Save your personalised week, get your due date, and book gynaecologists near you.

Browse pregnancy week by week