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Period: to
Week 1-2
No development -
Period: to
Week 3-4
Conception begins
Zygote turns into blastocyst and travels down the Fallopian tube.
Rapid cell division begins.
Blastocyst implants in uterus lining during week 4 and becomes an embryo. -
Weeks 5-6
Neural tube closes, brain and spinal cord form
heart, organ, bones start to form
head and trunk start to form
arm,leg, limb buds start to appear
brain begins development
eyes and ears form
heart continues to develop and beats a regular rhythm
baby is 1/6 inches long -
Period: to
Week 6-7
brain and face shape begin growing
four chamber heart
lungs begin to form
fingers and toes start to form
ears begin to develop
lip and nose have been formed
trunk and neck begin to strengthen
baby is about 1/2 inches long
all major organs are formed -
Period: to
Week 10
Head is half the size of the baby
all body parts are present
eyes, ears, arms, and legs are identifiable
baby is 1 1/4 inches long -
Period: to
Week 11
Genitals develop
head is about half the length of the baby
teeth buds form
baby is about 2 inches in length and weighs about 1/3 an ounce -
Week 12
Fingernails grow
Face has defined profile
intestines are abdomen
about 2 1/2 inches in length
1/2 ounce in weight -
Period: to
Week 14
Babies sex becomes apparent
Baby can swallow and make urine
baby is about 3 1/2 in length and weighs about 1 1/2 ounces -
Period: to
Week 16
Baby is moving but mom can not feel it
baby is about 4 1/2 inches in length and weighs about 4 ounces -
Week 18-19
Baby begins to hear
Digestive system works
vernix caseosa covers the baby -
Week 20-21
regular sleep and wake patterns
all organs and structures formed
breathing movements occur but are undeveloped
covered in Lanugo
may begin to suck thumb
baby is about 6 1/3 inches in length and weighs about 11 ounces -
Period: to
Week 22
Has nails and fingerprints, eyebrows, lashes, and possibly hair.
more active
heartbeat heard with a stethoscope
lowest limit of viability
baby is about 7 1/2 inches in length and weighs about 1 pounf -
Week 24
unrinkly 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 -
Week 28-29
Eyes begin to partially open and close
nervous system directs breathing and body temp control
lungs are capable of breathing air
baby begins to kick and strengthen
baby is about 10 inches and weighs about 2 1/4 pounds -
Period: to
Week 31-32
Finish most major development
rapid weight gain
lanugo starts to fall off
baby about 11 inches and weighs 3 1/4 pound -
Week 34
Continues to grow fingernails and toe nails
develop breathing motion
responds to light
skin is pink and smooth
baby is about 12 inches in length and 4 1/2 in pounds -
Period: to
Week 36-37
takes up most amniotic sac
starts to turn head down to prepare for labor
baby is about 13 1/2 inches in length and weighs 6 pounds
continues to gain 1/2 pound a week till delivery -
Week 38-40
Brain, lungs, and liver are still developing
brain will develop in size between weeks 35-39
Lungs development during last few weeks helps with fewer complications after birth
at week 39 baby is considered full term
weight gain helps with temp control once born