Third trimester

Week 39 of Pregnancy

"Full term" per ACOG.

Fetal size
Mini watermelon
Length
50.7 cm
Crown-to-heel
Weight
3.29 kg

Fetal development

  • Brain development continues at high speed.
  • Lungs are fully ready for first breaths.
  • Newborn body shape is essentially complete (~3.2–3.4kg).

Maternal changes

  • A sudden burst of energy ("nesting instinct") may appear.
  • Digestion and appetite can change.

Recommended checkups

  • Share the labor signs checklist with your family.

Jump to week

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