ANTEPARTUM

Stages of Pregnancy

 The third through eighth weeks after conception are called the embryonic stage.

 The fetal period starts 9 weeks after conception and laststhrough the end of gestation.

Fetal Development: Embryonic Stage

Week 1

 Free-floating blastocyst

Weeks 2 to 3

 The embryo is 1.5 to 2 mm long.

 Lung buds appear.

 Blood circulation begins.

 The heart istubular.

 The neural plate becomes the brain

and spinal cord.

Week 5

 The embryo is 0.4 to 0.5 cm long.

 The embryo weighs 0.4 g.

 Double heart chambers are visible.

 The heart beats.

 Limb buds begin to form.

Week 8

 The embryo is 3 cm long.

 The embryo weighs 2 g.

 The eyelids begin to fuse.

 The circulatory system through the

umbilical cord is well established