16 WEEKS PREGNANT
The fetus can now make small facial expressions
Baby this week: about 11.6 cm — crown to rump · about 100 g
≈ 11.6 cm — about the size of an avocado
Illustration enlarged for clarity — the amber marker shows true relative size
Your baby this week
- Tiny facial muscles allow subtle expressions like squints and frowns
- The circulatory system and urinary tract are fully functioning
- Toenails are starting to form, following the fingernails
- The heart is now pumping roughly 25 quarts of blood a day
Your body this week
- Some people start feeling the first faint flutters of movement around now, though it's often mistaken for gas this early
- A pregnancy glow — brighter skin and shinier hair — is common as blood volume and oil production increase
This week's tip: If you haven't scheduled your mid-pregnancy anatomy scan, ask your provider when it's typically done in their practice.
Want the bigger picture — organ development, nutrition, scans and warning signs for this stage? See month 4: Finding out who's in there.
Sizes and milestones are typical ranges — every pregnancy runs on its own clock. Educational content; your prenatal care team's guidance always comes first.