Placental Examination

Question 1

Give FOUR points of description of the placenta at term

Answer 1

• Is flat and round or oval in shape
• 18-20cm in diameter and up to 2.5cm thick in the centre
• Weights approximately 600g or a sixth of the baby’s birthweight
• Usually situated on anterior or posterior wall of the uterus near the fundus

Question 2

Give FIVE points of description of the maternal side of the placenta

Answer 2

• Is deep red in colour
• Divided by deep grooves (sulci) into 15-20 irregular lobes (cotyledons (contain the chorionic villi))
• Should look complete with no gaps
• Fibrin deposits may give it a greyish colour
• Calcification (lime salt deposits) may may it look gritty

Question 3

Give FOUR points of description of the fetal side of the placenta

Answer 3

• Lies adjacent to the fetus
• White shiny appearance
• Covered with amnion
• Insertion of the cord is usually central and the blood vessels can be seen radiating out to the peripheral edges

Question 4

Name the TWO types of fetal membranes

Answer 4

• Chorion

- Amnion

Question 5

List SIX things that describe the chorion

Answer 5

• It is the outer membrane
• Lines the uterine cavity
• Opaque and thick but friable
• Derived from the trophoblast
• Continuous with the edge of the placenta
• Produces prostaglandins and oxytocin

Question 6

List SIX things that describe the amnion

Answer 6

• It is the inner membrane
• Derived from the inner cell mass
• Smooth, transparent and the stronger of the two
• Amnion can be pulled back to insertion of cord
• Secretes amniotic fluid
• Produces prostaglandins

Question 7

What is a succenturiate lobe placenta?

Answer 7

When a small portion of lobe is separated from the main body. Attached to main placenta by blood vessels

Question 8

What is a circumvallate placenta?

Answer 8

When the chorion is attached not to the edge of the placenta but to the fetal surface some distance from the edge.

Question 9

What is a bipartite placenta?

Answer 9

When it is divided in to two lobes

Question 10

What is a tri-partite placenta?

Answer 10

When it is divided in to three lobes

Question 11

What is placenta accreta?

Answer 11

When it is abnormally adherant to the uterine muscle

Question 12

How many veins and arteries does the cord contain?

Answer 12

Two arteries and one vein

in the Jelly is an Artery a Vein and an Artery - JAVA

Question 13

Which membrane covers the cord?

Answer 13

Amnion

Question 14

Roughly how long and how thick is a cord?

Answer 14

50cm long and 2cm thick

Question 15

What is the composition of amniotic fluid?

Answer 15

• Clear straw coloured fluid
• 99% water and 1% solid matter
• Solid matter consists of: proteins, carbohydrates, lipids, and phospholipids, electrolytes, urea, uric acid, and creatinine, enzymes and placenta hormones
• Also contains fetal epithelial cells, vernix caseosa and laguno - makes liquid milky

Question 16

By 38 weeks, how many milliletres of amniotic fluid is there?

Answer 16

1000 - 1500ml

Question 17

What volume does the amniotic fluid decrease to after 38 weeks?

Answer 17

800ml

Question 18

List SEVEN functions of the amniotic fluid

Answer 18

• Provides a medium for fetus to move freely and effortlessly
• Equalize pressure
• To act as a shock absorber, protecting fetus
• Maintains a constant temperature
• Prevent pressure on the cord
• Provide some nutritive substance for the fetus
• During labour, it aids effacement and dilation of the cervix