Fetal thrombocytopenia

Fetal thrombocytopenia refers to an abnormally low platelet count in the fetus. The acceptable normal range for a fetal platelet count is similar to adults and do not vary significantly with gestation age. The lower limit for cut off is therefore usually taken as:

• 150,000/uL for thrombocytopenia and
• 50,000/uL for severe thrombocytopenia

Pathology

It is most often caused by maternal alloantibodies against fetal platelets crossing the placenta and resulting in platelet destruction. This condition, known as fetal and neonatal alloimmune thrombocytopenia (FNAIT) is considered a platelet equivalent of Rh isoimmunisation .

Other causes include:

• in utero infection(s)
• placental insufficiency
• idiopathic thrombocytopenic purpura (ITP)

Associations

Recognized associations include:

• radial ray anomalies
  • TAR syndrome
• placental chorioangioma 
• maternal autoimmune thrombocytopenic purpura: the fetus tends to develop thrombocytopenia in ~40-70% of cases .

Complications

• fetal intracranial hemorrhages

See also

• fetal anemia

Siehe auch:

• in utero infection
• fetal anaemia
• Plazentainsuffizienz
• Thrombozytopenie-Radiusaplasie-Syndrom
• Chorioangiom der Plazenta
• fetal intracranial haemorrhages
• Radialstrahldefekte

und weiter:

• Thrombozytopenie