-
Hour 1
Fertilization -
Fertilized egg
This is when the egg meets with the sperm and they merge their genetic information together -
Hour 12
Pronuclei join together -
Zygotic stage begins
The nuclear membrane od the ovum disappears at this point and 23 male chromosomes meet 23 female chromsomes -
Hour 30
First round of mitosis (cleavage) -
Hour 40
Second round of mitosis -
Hour 50
Third round of mitosis -
Embryonic stage begins
This occurs after the third mitosis -
Morula Formed
-
Day 6
64 cell embryo called a blastocyst -
Day 8
Implantation -
Day 10
Ectopic pregnancy could occur -
Hatching
-
Day 12
Disc with streak on the underside forms mesoderm -
Day 12
hCG begins to secrete -
Day 15
First missed period -
Day 16
Neural tube forms -
Day 22
The heart begins to beat, arm and leg buds appear, yolk sac makes RBCs -
Day 35
Face plates forming -
Day 36
Cleft lip or palate may occur -
Week 6
Muscles form, bent neck, webbed hands and feet, segmented back -
Week 7
Fingers and toes separate, eyes and ears formed -
Day 50
Genitalia begins to differentiate, eyelids fuse, amnion surrounds fetus -
Fetal stage begins
Occurs when all organs are formed -
Day 50
Amniocentesis can be performed -
Week 9
Chorionic villi sampling could be performed -
Month 6
Eyes open, fat added under skin, head out of proportion to the body
