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Period: to
Weeks 1-2
None -
Period: to
Weeks 3-4
-Conception
-Zygote turns into blastocyst and travels down the fallopian tubes
-Rapid cell division begins
-Blastocyst implants in uterus lining during week 4 and becomes an embryo -
Week 5-6
-Neural tube closes brain and spiral cord will form
-Heart, organs, and bones start to form
-Develop head and trunk
-Arm and leg limb buds appear -
Period: to
Weeks 7-8
-Brain and face shape begin growing
-Lungs begin to form
-Fingers and toes start to form
-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 -
Week 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 -
Period: to
Week 12
-Fingernails grow
-Face has a more defined profile
-Intestines are in the abdomen
-About 2 1/2 inches in length and weighs about 1/2 ounce -
Period: to
Week 14
-Baby's 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 -
Week 16
-Baby is moving but mom cannot feel it
-Baby is about 4 1/2 inches in length and weighs about 4 ounces -
Weeks 18-19
-Baby begins to hear
-Digestive system works
-Vernix caseosa covers the baby -
Weeks 20-21
-Regular sleep and wake patterns
-All organs and structures formed
-Breathing movements occur but are underdeveloped
-Covered in lanugo
-May start sucking thumb
-Baby is about 6 1/3 inches in length and weighs about 11 ounces -
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 of the mother)
-Baby is about 7 1/2 inches in length and weighs about 1 pound -
Week 24
-Wrinkly skin, Translucent and pinkish red
-Lung development
-Regular sleep and wake patterns
-Baby is about 8 inches in length and weights about 1 1/3 pounds -
Period: to
Weeks 28-29
-Eyes begin to partially open and close
-Central nervous system directs breathing and body temp control
-Lungs are capable of breathing
-Begins to kick and stretch
-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 -
Week 34
-Continues to grow fingernails and toenails
-Develop breathing motion
-Responds to light
-Skin is pink and smooth
-About 12 inches in length and weighs about 4 1/2 pounds. -
Period: to
Weeks 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 until delivery -
Period: to
Weeks 38-40
-Brain, Lungs, and liver still developing
-Brain will double in size between week 35-39
-Lung development during the last few weeks helped with fewer complications after birth
-Week 39, baby is full term
-Weight gain helps with temperature control once born