Fetal development

Fetal Developmental Timeline

  • Start

    Start

    Fertilization
  • Fertilized Egg

    Occurs when a sperm inserts into the egg
  • Zygote Stage Begins

    Occurs when the gamete of a male and female form together
  • 12 Hours

    12 Hours

    Pronuclei join together
  • 30-36 hours

    30-36 hours

    First round of mitosis (cleavage)
  • 40 hours

    40 hours

    Second Round of Mitosis
  • 50-60

    50-60

    Third Round of Mitosis
  • Morula Formed

    Morula Formed

  • 4-6 days

    4-6 days

    64 cell embryo called a blastocyst
  • Hatching

    Hatching

  • 7-8 days

    7-8 days

    Ectopic pregnancy could occur
  • 8-10 days

    8-10 days

    Implantation
  • Day 12

    Day 12

    Hcg begins to be secreted
  • Day 12

    Day 12

    Disc with streak on the underside forms mesoderm
  • 14-22 days

    14-22 days

    Neural tube forms
  • 15 days

    15 days

    First missed period
  • Embryo Stage Begins

    Occurs when a zygote is formed
  • Fetal Stage Begins

    Occurs when the embryo is growing from the 5th to 10th week
  • 21 days

    21 days

    Heart begins to beat, arm and leg buds appear, yolk sac makes RBCs
  • 34-36 days

    34-36 days

    Face plates forming
  • 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
  • 7th week

    7th week

    Fingers and toes separate, eyes and ears formed
  • 50 days

    50 days

    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
  • 6-7 months

    6-7 months

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