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10.4: Overview of Developmental Milestones

  • Page ID
    167219
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    WEEK CHANGES IN MOTHER DEVELOPMENT OF BABY
        Pre-embryonic Development
    1 week Ovulation Occurs Fertilization occurs, cell division begins and continues, chorion appears
        Embryonic Development
    2 weeks Symptoms of early pregnancy (nausea, breast swelling and tenderness, fatigue); blood pregnancy tests may show positive Implantation occurs; amnion and yolk sac appear; embryo has tissue; placenta begins to form
    3 weeks First period missed; urine pregnancy test may show positive; early pregnancy symptoms continue Nervous system begins to develop; allantois and blood vessels are present and placenta is well formed
    4 weeks   Limb buds form; heart is beating; nervous system further develops; embryo has tail; other systems are forming
    5 weeks Uterus is the size of a hen's egg; mother may need to urinate frequently Embryo is curved, head is large, limb buds are showing division, nose, ears and eyes are noticeable
    6 weeks Uterus is the size of an orange Fingers and toes are present and skeleton is cartilaginous
    8 weeks Uterus can be felt above the pubic bone Fetus begins to look human; limbs are developing and major organs forming; facial features are becoming refined
        Fetal Development
    12 weeks Uterus is the size of a grapefruit Head grows faster than the rest of the body; facial features are apparent, but there is no layer of fat yet and the skin is translucent; gender can be distinguished via ultrasound; fingernails appear
    16 weeks Fetal movement can be felt Fine hair (lanugo) grows over the body; fetus resembles a tiny human being; skeleton is visible
    20-22 weeks Uterus reaches up to the level of umbilicus and pregnancy is obvious Vernix caseosa, the protective fatty coating, begins to be deposited; heartbeat can be heard
    24 weeks Doctor can tell where baby's head, back and limbs are; breasts have enlarged and nipples and areola are darker, colostrum is produced Fully formed but still thin; much larger and very active, all major organs are working, the lungs and digestive system need more time to develop; body is covered in fine hair called lanugo
    32 weeks Uterus reaches halfway between umbilicus and rib cage Most babies are in a head down position in the womb; head is more in proportion to the body; eyes are open; babies born at this stage have a good chance of living
    36 weeks Weight gain is averaging about a pound a week; standing and walking are becoming very difficult because the center of gravity is thrown forward Body hair begins to disappear, fat is being deposited
    40 weeks Uterus is up to the rib cage, causing shortness of breath and heartburn; sleeping is very difficult Not much room to move in the womb; fully mature, baby