-
Period: to
weeks 1-2
none -
Period: to
weeks 3-4
- conception
- zygote turns into blastocyst and travels down the fallopian tube
- rapid cell division begins
- blastocyst implants in uterus lining during week 4 and becomes and embryo
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Period: to
weeks 5-6
- neural tube closes; brain and spinal cord will form
- heart, organs, and bones start to form
- develop head and trunk
- arms and leg limb buds appear
- brain begins development -eyes and ears begin to form
- heart continues to develop, and beats a regular rhythm
- baby is 1/6 inch long
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Period: to
weeks 7-8
- brain and face shape begin growing
- four- chamber heart
- lungs begin to form
- fingers and toes start to form
- ears begins to develop internally
- lip and nose have formed
- trunk and neck begin to straighten
- baby is about 1/2 inch long
- all major organs are formed
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week 10
- head is half the size of the baby
- all body parts are present
- eyes, ears,arms, and legs are identifiable
- baby 1 1/4 inches long
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weeks 11
- genitals develop
- head is about half of the length of baby
- teeth buds form
- baby is about 2 inches in length and weighs about 1/3 ounce
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Period: to
week 12
- fingernails grow
- face has more defined profile
- intestines are in the abdomen
- about 2 1/2 inches in length and weighs about 1/2
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Period: to
week 14
- babys sex will become apparent
- baby can swallow and make urine
- baby is about 3 1/2 inches in length and weighs about 1 1/2 ounces
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week 16
- baby is moving but mom cannot feel it
- baby is about 4 1/2 inches in length and weighs about 4 ounces
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week 18-19
- baby begins to hear
- digestive system works
- vernix caseosa covers the baby
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Period: to
weeks 20-21
- regular sleep and wake patterns
- all organs and structures formed
- breathing movements occur but are underdeveloped
- covered in lanugo
- may begin to suck thumb
- baby is about 6 1/3 inches in length and weighs about 11 ounces
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Period: to
week 22
- has nails, fingerprints, eyebrows,lashes,and possibly some hair
- more active
- heartbeat heard with a stethoscope
- lowest limit of viability ( survival outside the mother
- baby is about 7 1/2 inches in length and weighs about 1 pound
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week 24
- wrinkly skin, translucent and pinkish red
- lung development
- regular sleep and wake patterns
- baby is about 8 inches in length and weighs about 1 1/3 pounds
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Period: to
week 28-29
eyes begin to partially open and close
- central nervous system directs breathing and body temperature control
- lungs are capable of breathing air
- baby begins to kick and stretch
- baby is about 10 inches in length and weighs about 2 1/4 pounds -
weeks 31-32
- finished most major development
- rapid weight gain begins
- lanugo starts to fall off
- baby is about 11 inches in length and weighs about 3 3/4 pounds
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week 34
- continues to grow fingernails and toenails
- develop breathing motion
- respond to light
- skin is pink and smooth
- baby is about 12 inches in length and weighs about 4 1/2 pounds
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week 36-37
- takes up most of the amniotic sac
- starts to turn head down to prepare for labor
- baby is about 13 1/2 inches in length and weighs about 6 pounds
- will continue to gain about 1/2 pound a week before delivery
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weeks 38-40
- brains, lungs and liver still developing
- brain will double in size between week 35&39
- lung development during last few weeks helps with fewer complications after birth
- at week 39, baby is considered full term
- weight gain helps with temperature control once born