What Is A Decidual Cast? How It Relates to Pregnancy Loss or Heavy Period

decidual cast

Before we let you know what a decidual cast is, let’s help you with what happens when you come across heavy bleeding right after getting pregnant. The post will also narrate some facts regarding miscarriage complications.


What Is a Decidual Cast?

Have you ever heard the term Decidual cast? It’s basically a large intact piece of tissue that gets passed through vagina in one solid piece.

You might be wondering the reason behind this. Well, the main reason of the formation of decidual cast is the shedding of a thick lining of mucous  (also known as decidua) from uterine cavity. While it sheds out from the uterine cavity, it creates a triangular ‘cast’.

The above condition is also called as membranous dysmenorrhea which happens while having your period.

Although, the main reason of the formation of decidual cast is not known, most physicians believe it happens due to ectopic pregnancy (a pregnancy that forms outside uterus).

It can also be linked to some type of hormonal interference. One reason can be due to hormonal contraceptives with progesterone.


Decidual Cast Symptoms

When the formation of decidual cast happens, it sometimes becomes difficult to pass it due to extreme pain. In the days while you pass it, you can have symptoms like:

  • Severe discomfort
  • Heavy vaginal bleeding
  • Painful stomach cramps

But once you are able to pass the decidual cast, you start getting relief and the symptoms associated with it will get disappear. Once out, the cast looks solid, fleshy and pink.

Sometimes, it has shiny appearance as it is made up of tissue which itself made up of blood and mucous (clubbed together).


What Causes Decidual Cast

There are only a handful of cases where decidual cast are reported. In cases where people have reported it, they are found to be aged from 9 to 41 years.

Although, doctors are still finding the exact reason that causes decidual cast, there are some other reasons associated with it like:


Hormonal contraceptives

One reason of the formation of Decidual casts is associated with the use of hormonal birth control having progesterone.

Most of the time, these contraceptives are taken through mouth. They are sometimes implanted or even injected too.


Ectopic pregnancy

It happens when the pregnancy happens outside of the uterus. It means the formation of embryo happens outside of the uterus.

The most common place of the formation of embryo happens in one of your fallopian tubes. There are cases where it has been found to happen in abdominal cavity or ovaries.

In cases where embryo gets ruptured, it leads to internal bleeding which can be a life threatening event.

Please note that you can’t carry ectopic pregnancy to term. The best way to rectify is to consult the doctor concerned.



Sometimes, there are some other conditions responsible that cause similar symptoms.

In order to confirm a decidual cast, the doctor has to first rule out other conditions causing similar symptoms like:

  • Ectopic pregnancy
  • Miscarriage
  • Pregnancy
  • Polyps
  • Benign or cancerous tumors

In addition to this there can be some other conditions associated with it.



When you have the condition of decidual cast, you will most probably pass it in one single piece.

In such cases, your doctor recommends a transvaginal ultrasound to check if all the tissue has been passed.

Once you pass it, you will get rid of the symptoms associated with it. Please note that a decidual cast is not a signal of any other type of condition. Even with side effects, there are no records of people having long term negative effects.

So, if you come across symptoms like pain or cramp or having the issue of pass lumps of tissue from your vagina, it may happen due to some irregular bleeding patterns. In such cases, you need to let your doctor know about it.

In addition to this, you have some other side effects a[art from decidual cast, it can be due to your birth control pill containing progesterone. In such cases, you need to consult with your doctor.


Also Read: Honey Impact: Are There Any Health Benefits of Organic Honey?