Clinical consequences of poor placentation II

Question 1

What are the 4 causes of foetal smallness

Answer 1

1) Dating problems
2) Constitutional
3) Environmental problem
4) Placental insufficiency

Question 2

Foetal/environmental reasons for smallness

Answer 2

• Chromosomal abnormalities
(e.g. Trisomy 18, Triploidy)
• Congenital infections
(e.g. Rubella, CMV)
• Genetic syndromes
(e.g. Russell-Silver syndrome)
• Teratogens
(e.g. Fetal alcohol syndrome, Drug abuse)
• Maternal problem
(e.g. Cyanotic CHD)

Question 3

Describe placental insufficiency as a cause of smallness

Answer 3

Placenta function is nutrient and gas
exchange
• Poor function will lead to:
• Slowing of growth
• Hypoxaemia – Hypoxia – Asphyxia
• Stillbirth
• Ultrasound used to find evidence of
• Placental dysfunction
• Fetal response to the dysfunction

Question 4

What to take account for in placental insufficiency in a clinical setting

Answer 4

Risk factor
• Previous history
• Positive uterine arterial Doppler screen
• Abnormal placental echo-texture
• AC below the 5th centile

Doppler changes can be noted in a pregnancy with poor placental insufficiency
things we can note:
Poor placentation
Increased umbilical PI (Pulsatility index)
Redistribution
Decompensation

Question 5

What are some methods for detecting FGR

Answer 5

Clinical – Symphysis-fundal height

One trial with 1639 women was available
• Antenatal detection of small babies was
lower in the fundal height group (28%)
than abdominal palpation (48%)

• No evidence of improved outcome
• Serial Ultrasound biometry
• Uterine artery Doppler screening

Question 6

Pre term FGR

Answer 6

Diagnosis, fetal response and monitoring
is well characterized
• Pathophysiology and natural history is
understood

Question 7

FGR between 28-36 weeks

Answer 7

•Increased PI in Umbilical artery is abnormal.
•Deliver for reversed EDF > 32 weeks
•Deliver for absent EDF > 34 weeks
•MCA Dopplers not needed if Umbilical
artery Dopplers are normal.

Question 8

FGR >36 weeks

Answer 8

Increased PI in Umbilical artery is
abnormal. Consider delivery.
• Normal Umbilical artery PI alone is not
enough.
• MCA Dopplers needed even if Umbilical
artery Dopplers are normal. Consider
delivery if MCA PI < 5th centile.