40 WEEKS PREGNANT
Your due date arrives, though most babies arrive within a couple of weeks of it either way
Baby this week: about 51 cm — head to heel · about 3.4 kg
≈ 51 cm — about the size of a small watermelon
Illustration enlarged for clarity — the amber marker shows true relative size · head-down, ready position
Your baby this week
- The baby is fully developed and ready to be born, though every pregnancy reaches this point on its own timeline
- Vernix and lanugo are mostly gone, though some babies are born with a bit remaining
- The skull bones remain flexible to help ease the journey through birth
- Reflexes like grasping, sucking, and rooting are all ready to go
Your body this week
- Only a small percentage of babies actually arrive on their exact due date — most arrive within about two weeks before or after
- Strong, regular, intensifying contractions are typically the sign that labor has truly begun
This week's tip: If you go past your due date, ask your provider what monitoring or options they typically discuss for the days that follow — every pregnancy and practice varies.
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.