Fetal Development Timeline

By allison.reedBDHS
  • Fertilization

    Fertilization

  • Fertilized Egg

    Begins to exist when sperm enters the egg
  • pronuclei join together

    pronuclei join together

  • Zygote Stage Begins

    Occurs when the pronuclei join together
  • first round of mitosis (cleavage)

    first round of mitosis (cleavage)

  • second round of mitosis

    second round of mitosis

  • third round of mitosis

    third round of mitosis

  • Embryo Stage Begins

    occurs after third mitosis
  • morula forms

    morula forms

  • hatching

    hatching

  • 64 cell embryo called a blastocyst forms

    64 cell embryo called a blastocyst forms

  • ectopic pregnancy could occur

    ectopic pregnancy could occur

  • implantation

    implantation

  • disk with streak on the underside forms the mesoderm

    disk with streak on the underside forms the mesoderm

  • hCG begins to be secreted

  • neural tube forms

    neural tube forms

  • first missed period

  • heart begins to beat, arm and leg buds appear, yolk sac makes RBCs

    heart begins to beat, arm and leg buds appear, yolk sac makes RBCs

  • face plates forming

    face plates forming

  • cleft lip or palate may occur

    cleft lip or palate may occur

  • muscles form, bent neck, webbed hands and feet, segmented back

    muscles form, bent neck, webbed hands and feet, segmented back

  • fingers and toes separate, eyes and ears form

    fingers and toes separate, eyes and ears form

  • genetalia begins to differentiate, eyelids fuse, amnion surrounds fetus

    genetalia begins to differentiate, eyelids fuse, amnion surrounds fetus

  • Fetal Stage Begins

    occurs when genetalia begins to differentiate
  • chorionic villi sampling could be performed

    chorionic villi sampling could be performed

  • amniocentesis could be performed

    amniocentesis could be performed

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

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