Baby Development
3 Weeks
The rudiments of the respiratory, digestive, circulatory, nervous and excretory systems are formed. The heartbeat starts.
4 Weeks
The rudiments of the intestine, liver, kidney and lung are formed. The muscular system and the spine are formed. The formation of the neural tube is completed
5 Weeks
Organs and systems start to form, as do parts of the brain. The umbilical cord appears. The upper lip and nasal cavity are formed, as are the rudiments of the extremities and nails.
6 Weeks
The brain and its divisions form, The formation of the placenta and the muscles of the face begin. The rudiments of the hands and finger form.
7 Weeks
The uteroplacental circulation starts. The upper limbs are developed. The eyes and rudiments of the auricles start to form.
8 Weeks
The heart. lungs, brain, urinary system and reproductive system are formed. Eyes, eyelids, nose, ears and the formation of the lips are completed.
14 Weeks
The first hair appears and the bones become more robust. Changes take place in the genital organs - the prostate gland forms in the boys and ovaries migrate to the pelvic cavity in girls.
18 Weeks
The immune system is created. The modes of sleep and wakefulness begin to take affect. The baby has the ability to distinguish sounds and see the surrounding world.
24 Weeks
The bone marrow and spleen start to product blood cells. Taste buds are developed. The face is fully formed, including eyelashes and eyebrows, which can be seen on baby scans.
32 Weeks
The folds start to disappear. Hands and feet become more plump. The skin ceases to be red. The endocrine system begins to secrete hormones. The lungs accumulate surfactant.
36 Weeks
Subcutaneous fat develops. The bones of the skull remain soft with gaps (fontanelles). The baby experiences a continued weight gain and growth.
39 Weeks
The three-dimensional image can be perceived of the brain. The eye focuses on the distance of 30cm. The fuzz has disappeared, the baby has hair on its head. The baby is ready for birth.
