Obstetric and Gynecological Nursing - The Carter Center

Appearance of the Placenta at Term
The placenta measures about 20 cm in diameter and 2.5cm
thick from its center. It weighs approximately one sixth of the
baby’s weight at term. It has two surfaces.
1. The maternal surface maternal blood gives this surface a
dark red colour and part of the basal decidua will have
beenseparated with it. The surface is arranged in about
20 lobes which are separated by sulci
2. The fetal surface. The amnion covering the fetal surface
of the placenta gives it a whitish, shiny appearance.
Branches of the umbilical veins and arteries are visible
and spreading out from the insertion of the umbilical cord
which is normally in the center.
The aminotic sac consists of a double memberane.
Chorion – Outer layer adher to the uterine wall.
Amnion.-The inner layer of the aminotic sac containing an
aminotic fluid and cover the fetal surface of the placenta and
are what give the placenta its typical shiny appearance.
Protects the fetus from any infection and the amniontic fluid is
a clear, pale straw in colour.It secreted by the amnion and
fetal urine also contributes to the volume from the 10 th weeks
of the gestation on wards.The total amount of amniotic fluid is
45