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weeks 1-2
In weeks 1-2 the zygote turns into a blastocyst and rapid cell division begins. -
weeks 3-4
In weeks 3-4 the fetus' neural tube closes, the spinal cord will begin to form, heart, organs, bones will start to form and the fetus will start to develop the head and trunk. The baby is 1/6 inch long. -
weeks 5-6
In weeks 5-6 baby's heart,organs and bones continue to form. The baby forms its head and trunk. The baby's eyes and ears start to form and the baby is 1/6 inch long. -
weeks 7-8
In weeks 7-8 the baby's face and brain start forming, it forms a 4 chamber heart, the limbs, toes and fingers start to form, the ears internally develop and baby is 1/2 inch long. -
week 10
At week ten all body parts are present, Eyes, ears, And limbs are identifiable and baby is 1 1/4 inches long. -
week 11
at week 11 baby's genitals develop, head is half the length of the baby, teeth buds form and baby is 2 inches long. -
week 12
at week 12 the baby develops fingernails, the baby's face is more defined, the intestines are fully developed and the baby is 2 1/2 inches long. -
week 14
at week 14 the baby's sex will be apparant, it will be able to make urine and swallow and the baby is 3 1/2 inches long. -
week 16
At week 16 baby starts to move but the mother cannot feel it, The baby is 4 1/2 inches and weighs 4 ounces. -
weeks 18-19
At weeks 18-19 baby begins to hear, the digestive system works and the vernix caseaus covers the baby. -
weeks 20-21
at weeks 20-21 the baby develops a regular sleep cycle, the baby's organs and structure is fully developed, the baby can breath shallow breaths, its covered in lanugo at this point and is 6 1/3 inches long. -
week 22
At week 22 the baby has nails, finger prints and lashes, the baby is more active, the heartbeat can be heard with a stethiscope and is 7 1/2 inches long -
week 24
at week 24 the baby develops wrinkly skin, the lungs are fully developed, and the baby is 8 inches. -
week 28-29
in weeks 28-29 the eyes begin to open and close, the nervous system works, the lungs can breath air, it begins to stretch and move and its 10 inches. -
weeks 31-32
at weeks 31-32 the baby has finished its major development, the baby has a major weight gain, the lanugo falls off and it is 11 inches long. -
week 34
at week 34 the baby continues to grow fingernails, develops a breathing motion, responds to light, skin is pink and smooth and is 12 inches long -
Weeks 36-37
At weeks 36-37 the baby takes up most of the amniotic sac, it starts to turn its head down for labor and is 12 inches long. -
weeks 38-40
at weeks 38-40 the brain, lungs and liver are done developing, the brain will double in size.