At 4 weeks
- Your baby's brain and spinal cord have begun to form
- The heart begins to form
- Face and neck begin to form
- Arm and leg buds appear
- Lungs, stomach and liver start to develop
At 8 weeks
- The baby is a little over half an inch in size
- All major organs and external body structures have begun to form
- Your baby's heart beats with a regular rhythm
- The arms and legs grow longer, and fingers and toes have begun to form
- The sex organs begin to form
- The eyes have moved forward on the face and eyelids have formed
- The umbilical cord is clearly visible
At 12 weeks
- The baby is about 2 inches in size
- The nerves and muscles begin to work together
- Your baby can make a fist
- The external sex organs should start becoming clear
- Eyelids close to protect the developing eyes. They will not open again until the 28th week
- Head growth has slowed, and your baby is much longer
