Image 1: There are thin, flake-like fetal squamous cells and acellular eosinophilic mucin within the pulmonary arteries.

Image 2: Thin squamous cells within pulmonary arteries -- it can be subtle.

Image 3: The squames within this arteriole is a little more obvious.

Amniotic fluid embolism is a rare and often fatal complication of pregnancy. Clinically, amniotic fluid embolism presents with sudden onset of difficulty breathing, low blood pressure, seizures, followed by cardiac arrest.

This 28 year old woman died of amniotic fluid embolism. She was admitted to the hospital for induction of labor and soon after the anesthesiologist started medications, she became unresponisve. She had an emergency caesarean section and delivered a healthy infant, however, the mother could not be resuscitated and was pronounced dead.