Human Fetal Development

By marciestoots

  • Fertilized Egg

    Begins when the sperm meets the egg

  • Start

    Start
    Fertilization

  • Hour 12

    Hour 12
    Pronuclei join together

  • Zygote Stage Begins

    Occurs when the pronuclei join together

  • Hour 36

    Hour 36
    First round of mitosis

  • Hour 40

    Hour 40
    Second round of mitosis

  • Embryo Stage Begins

    Occurs after the third round of mitosis

  • Hours 50-60

    Hours 50-60
    Third round of mitosis

  • Day 6

    Day 6
    64 cell embryo called a blastocyst

  • Morula formed

    Morula formed

  • Hatching

    Hatching

  • Days 7-8

    Days 7-8
    Ectopic pregnancy could occur

  • Days 8-10

    Days 8-10
    Implantation

  • Day 12

    hCG begins to be secreted

  • Day 12

    Day 12
    Disc with streak on the underside forms mesoderm

  • Day 15

    First missed period

  • Day 21

    Day 21
    Heart begins to beat, arms and leg buds appear, yolk sac makes RBCs

  • Days 14-22

    Days 14-22
    Neural tube forms

  • Days 34-36

    Days 34-36
    Face plates forming

  • Days 34-36

    Days 34-36
    Cleft lip or palate may occur

  • Week 6

    Week 6
    Muscles form, bent neck, webbed hands and feet, segmented back

  • Week 7

    Week 7
    Fingers and toes separate, eyes and ears formed

  • Fetal Stage Begins

    Occurs when all the organs are formed

  • Day 50

    Day 50
    Genitalia begins to differentiate, eyelids fuse, amnion surrounds fetus

  • Weeks 9-11

    Weeks 9-11
    Chorionic villi sampling could be performed

  • Weeks 14-15

    Weeks 14-15
    Amniocentesis could be performed

  • Months 6-7

    Months 6-7
    Eyes open, fat added under skin, head out of proportion to body