HESI PN MATERNITY PROCTORED EXAM VERSION 6 (2026/2027) (Verified Answers) (45pages)

ANTEPARTUM

Stages of Pregnancy

ï‚· The third through eighth weeks after conception are called the embryonic stage.

ï‚· The fetal period starts 9 weeks after conception and laststhrough the end of gestation.

Fetal Development: Embryonic Stage

Week 1

ï‚· Free-floating blastocyst

Weeks 2 to 3

ï‚· The embryo is 1.5 to 2 mm long.

ï‚· Lung buds appear.

ï‚· Blood circulation begins.

ï‚· The heart istubular.

ï‚· The neural plate becomes the brain

and spinal cord.

Week 5

ï‚· The embryo is 0.4 to 0.5 cm long.

ï‚· The embryo weighs 0.4 g.

 Double heart chambers are visible.

ï‚· The heart beats.

ï‚· Limb buds begin to form.

Week 8

ï‚· The embryo is 3 cm long.

ï‚· The embryo weighs 2 g.

ï‚· The eyelids begin to fuse.

ï‚· The circulatory system through the

umbilical cord is well established