37 WEEKS PREGNANT
Early term begins as the lungs finish maturing
Baby this week: about 48 cm — head to heel · about 2.9 kg
≈ 48 cm — about the size of a bundle of romaine lettuce
Illustration enlarged for clarity — the amber marker shows true relative size · head-down, ready position
Your baby this week
- The lungs are close to fully mature, an important milestone for breathing after birth
- A firm grasping reflex has developed in the hands
- The baby continues gaining fat, which helps with temperature regulation after birth
- Most babies are now in a head-down position, preparing for delivery
Your body this week
- Nesting instincts — a burst of energy to prepare and organize — are common around this point
- Pelvic pressure and more frequent trips to the bathroom often continue
This week's tip: If you haven't finished your hospital bag, aim to have it ready by now — many providers suggest packing it by around week 36.
Want the bigger picture — organ development, nutrition, scans and warning signs for this stage? See month 9: The waiting month.
Sizes and milestones are typical ranges — every pregnancy runs on its own clock. Educational content; your prenatal care team's guidance always comes first.