Embryo

Human Fetal Development

By lpolhamus

  • Start

    Start
    Fertilization

  • Fertilized Egg

  • 12 hours

    12 hours
    pronuclei join together

  • Zygote Stage Begins

  • 30 - 36 Hours

    30 - 36 Hours
    first round of mitosis [cleavage]

  • 40 Hours

    40 Hours
    second round of mitosis

  • 50-60 Hours

    50-60 Hours
    third round of mitosis

  • Morula Formed

    Morula Formed

  • Ectopic Pregnancy Could Occur

    Ectopic Pregnancy Could Occur

  • Day 4

    Day 4
    64 cell embryo called a blastocyst

  • Hatching

    Hatching

  • Embryonic Period Begins

  • Day 10

    Day 10
    Implantation

  • hCG begins to be secreted

  • Day 15

    First Missed Period

  • Day 21

    Day 21
    disc with streak on the underside forms mesoderm

  • Day 22

    Day 22
    Heart begins to beat, arm & leg buds appear, yolk sac makes RBCs

  • Day 28

    Day 28
    Neural tube forms

  • Days 34, 35 & 36

    Days 34, 35 & 36
    Face plates come together

  • Cleft Lip or Palate may occur

    Cleft Lip or Palate may occur

  • 6th Week

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

  • 7 Weeks

    7 Weeks
    fingers & toes separate, eyes & ears are formed

  • Fetal Period begins

    Fetal Period begins

  • Day 50

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

  • 9-11 Weeks

    9-11 Weeks
    chorionic villi sampling could be performed

  • 14-15 Weeks

    14-15 Weeks
    amniocentesis could be performed

  • 6 Months

    6 Months
    eyes open, fat added under skin, head out of proportion to the body