Fetal Development

By Natalie.Guisinger
  • Day 1 Hour 1

    Day 1 Hour 1

    Fertilization

  • Fertilized Egg

    Occurs when the sperm penetrates the egg and the 2 prepare to exchange chromosomes.

  • Zygote Stage Begins

    Occurs when the cell undergoes the first stage of mitosis
  • Hour 12

    Hour 12

    Pronuclei Join Together
  • Hour 33

    Hour 33

    1st Round of Mitosis
  • Hour 40

    Hour 40

    2nd Round of Mitosis
  • Hour 55

    Hour 55

    3rd Round of mitosis, cell becomes morula.
  • Hour 60

    Hour 60

    Hatching
  • Day 4

    Day 4

    64 cell embryo becomes blastocyst
  • Day 9

    Day 9

    Implantation
  • Day 12

    Day 12

    hCG begins to be secreted.
    Disc with streak on the underside forms mesoderm.

  • Embryo Stage Begins

    Occurs when the implanted blastocyst forms a disc in the mesoderm that will become the baby.

  • Day 15

    First missed period
  • Day 18

    Day 18

    Neural Tube forms
  • Day 21

    Day 21

    Heart begins to beat, arm & leg buds appear, yolk sac makes RBCs.
  • Day 35

    Day 35

    Face plates form.
  • 5-8 weeks

    5-8 weeks

    Clef Lip or palate may occur.
  • Week 6

    Week 6

    Muscles form, bent neck, webbed hands & feet, segmented back.
  • Week 7

    Week 7

    Fingers & toes separate, eyes & ears form.
  • Day 50

    Day 50

    Genitalia begins to differentiate, eyelids fuse, amnion surrounds fetus.
  • Week 9

    Week 9

    Ectopic pregnancy can occur

  • Fetus Stage Begins

    The fetus stage begins when all organs and body parts are present at Week 9.
  • 9-11 Weeks

    9-11 Weeks

    Chorionic villi sampling can be performed.
  • Week 14

    Week 14

    Amniocentesis can be performed
  • 6-7 months

    6-7 months

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