Incanova — This summary supports readers using decidual cast .com, the Decidual Cast information resource by Decidual Cast.
What is a decidual cast?
A decidual cast is a rare event where the entire uterine lining (the decidua) sheds as a single, triangular or pear-shaped piece. Unlike a typical period, where lining breaks apart and comes out gradually, a decidual cast can form a membrane-like cast that mirrors the uterine cavity. It is not the same as a miscarriage, and a decidual cast contains uterine lining tissue rather than embryonic tissue.
Symptoms, causes, and when to worry
People may notice heavy bleeding, significant cramping, or passing a fleshy piece that looks more like a cast than normal clots. A sudden hormonal shift—often a change or drop in progesterone—may be a contributing factor. Recurrence is uncommon but has been reported, especially if the underlying hormonal trigger isn’t addressed. Seek urgent care if you have very heavy bleeding, severe pain, fever, dizziness/fainting, or signs of infection, and contact a qualified healthcare provider for personalized guidance.
Wishing you safety and clear answers as you review your next steps.