Placental insufficiency

Placental insufficiency is a term given to a situation where the placenta cannot bring enough oxygen and nutrients to the growing fetus.

Clinical presentation

Fetuses may present with intra-uterine growth restriction (IUGR) (especially asymmetrical IUGR).

Pathology

It can be primarily caused by three main mechanisms ⁴:

• impairment in maternal circulation
  • maternal hypertension
  • maternal thrombophilic disorders
• impairment in fetal circulation
  • placental implantation over a fibroid
• vascular thrombosis (e.g. placental infarction)

Risk factors

• maternal narcotic (cocaine/heroin) use

Radiographic assessment

Ultrasound

• may show a reduction in fetal biometric parameters, i.e. showing a picture of IUGR
• amniotic fluid volumes may be low, i.e. oligohydramnios

In chronic placental insufficiency, there is often abnormal umbilical arterial Doppler with traces showing a reduction, absence, or reversal, of end-diastolic flow. 

Fetal MRI

Not part of a routine investigation. There are some reports suggesting the presence of restricted diffusion and reduced ADC values on MRI ².