Third trimester

Week 40 of Pregnancy

The due date arrives. About 90% of births occur within ±2 weeks of the EDD; only ~5% land on the exact day.

Fetal size
Watermelon
Length
51.2 cm
Crown-to-heel
Weight
3.46 kg

Fetal development

  • All organs are fully prepared for birth.
  • Average weight ~3.4kg, length ~51cm.
  • Placental aging begins late in pregnancy and may require closer monitoring.

Maternal changes

  • Birth ±2 weeks from the EDD is normal.
  • After 41 weeks, your OB may discuss induction.

Recommended checkups

  • Non-stress tests (NST) and amniotic fluid checks become more frequent after 40 weeks.

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Textbook averages. Individual variation is wide and this is not medical advice — confirm with your OB.