Lecture Notes

Fetal Brain Insults of Placental Origin

• The placenta plays critical roles in fetal brain development including endocrine support, growth factor provision, respiratory function, and nutrient supply.
• Placental failure predominantly impacts respiratory and nutrient functions, significantly affecting fetal neurodevelopment.

Placental Respiratory Failure

• Occurs when placental gas exchange is compromised, leading to fetal hypoxemia and acidosis.
• Potential mechanisms include decreased uteroplacental perfusion, increased villous membrane diffusion distance, decreased maternofetal circulatory interface, fetal anemia, and fetal circulatory anomalies.
• Fetal compensatory mechanisms (e.g., peripheral vasoconstriction) may become overwhelmed, leading to fetal acidemia and hemodynamic compromise.
• Severe lactacidosis disrupts peripheral vasoconstriction, myocardial function, and cerebral autoregulation, precipitating fetal brain injury.

Placental Ischaemic Disease

• Includes fetal growth restriction (FGR), placental abruption, and pre-eclampsia.
• Commonly arises from impaired trophoblast invasion and abnormal placentation.
• These conditions significantly elevate fetal and neonatal mortality and risk of long-term neurodevelopmental impairment.
• These diseases are major contributors to preterm birth and subsequent brain injury.