- Pregnancy at 1-3 Weeks
- Pregnancy at 4 Weeks
- Pregnancy at 5 Weeks
- Pregnancy at 6 Weeks
- Pregnancy at 7 Weeks
- Pregnancy at 8 Weeks
- Pregnancy at 9 Weeks
- Pregnancy at 10 Weeks
- Pregnancy at 11 Weeks
- Pregnancy at 12 Weeks
- Pregnancy at 13 Weeks
- Pregnancy at 14 Weeks
- Pregnancy at 15 Weeks
- Pregnancy at 16 Weeks
- Pregnancy at 17 Weeks
- Pregnancy at 18 Weeks
- Pregnancy at 19 Weeks
- Pregnancy at 20 Weeks
- Pregnancy at 21 Weeks
- Pregnancy at 22 Weeks
- Pregnancy at 23 Weeks
- Pregnancy at 24 Weeks
- Pregnancy at 25 Weeks
- Pregnancy at 26 Weeks
- Pregnancy at 27 Weeks
- Pregnancy at 28 Weeks
- Pregnancy at 29 Weeks
- Pregnancy at 30 Weeks
- Pregnancy at 31 Weeks
- Pregnancy at 32 Weeks
- Pregnancy at 33 Weeks
- Pregnancy at 34 Weeks
- Pregnancy at 35 Weeks
- Pregnancy at 36 Weeks
- Pregnancy at 37 Weeks
- Pregnancy at 38 Weeks
- Pregnancy at 39 Weeks
- Pregnancy at 40 Weeks
How Your Baby Has Grown 12 Weeks
Your baby's development
Skin and hair:
Skin is translucent. Fingers and toes are no longer webbed and nails are beginning to develop.
Muscles:
Developing muscles are linked with the nervous system. The diaphragm has formed.
Bones:
All bones are in place. Bones continue to harden.
Organs:
All major internal organs are formed, but still maturing.
Circulatory system:
This is fully functioning. The heart is pumping blood.
Digestive system:
Fully formed and fuctional.
Endocrine system:
This is starting to manufacture growth hormone and produce alphafetoprotein.
Nervous system:
The brain is now complete but still developing. Messages pass between the spinal cord and muscles.
Renal system:
Kidneys are functioning.
Respiratory system:
Your baby is practising breathing movements.
Ears:
Outer ears have moved from the neck to the side of the head. The outer ear continues to develop but the middle and inner ears are fully formed.
Eyes:
Eyes, although still wide apart, have moved from the sides of the head to the front. Eyelids are fused shut.