Foetus in Foetu

Foetus in Foetu, also called cryptodidymus, is a rare congenital disorder where a malformed fetus is found within its twin, often mistaken for a tumor.

Foetus in Foetu

Foetus in Foetu Latest News

Recently, doctors at the Buldhana District Women’s Hospital in Maharashtra detected a rare case of “foetus in foetu” in a pregnant woman.

About Foetus in Foetu

  •  It is a rare congenital disorder which is also known as cryptodidymus.
  • It is a foetus-like mass developed within the body of the other foetus in a monozygotic twin pregnancy.
  • Basically, one twin is very underdeveloped and enwrapped inside the body of the other twin, so much so that the pregnancy is considered a singleton pregnancy.
  • The presence of a twin inside the body of the other twin may go undetected for years.
  • This condition occurs when a malformed foetus develops inside another foetus. 
  • It affects about one in 500,000 births. Less than 200 cases have been reported worldwide, with about 10 to 15 cases in India.

Causes of Foetus in Foetu

  • The exact cause of this condition is not fully understood, but it’s believed to result from an anomaly during the development of monozygotic or identical twins. 
  • About 10 to 15 days after the conception of monozygotic twins, the cell mass of the embryo may be split unevenly, due to which one twin is smaller and incompletely formed with the other twin fully developed. 
  • The smaller twin gets trapped within the larger twin. The trapped twin is considered “parasitic,” as it draws its blood supply and nutrients from the other “host” twin.
  • The trapped or “parasitic twin” has some morphologic features of a normal foetus such as an umbilical cord-like structure, a bag of membranes surrounding it, and blood vessel connections to the host twin. It may have a vertebral column, limbs, and a few organs but lacks vital organs like the brain, heart or gut. Despite having “living tissue,” the parasitic twin has no prospects of independent existence outside the host twin. 
  • The presence of the parasitic twin affects the health of the host twin, who has to “feed” the former from the nutrients received over a single umbilical cord. In addition, enlargement of the trapped parasitic twin may compress vital organs in the host and cause discomfort or life-threatening complications.
  • Generally, the parasitic twin is found in the abdomen of the host twin. Rarely, it may be found in other organs like the brain or chest. 

Foetus in Foetu FAQs

Q1: What is a Fetus in Fetu in the uterus?

Ans: It is a rare congenital anomaly in which a malformed fetus grows within the body of its twin.

Q2: What is called a foetus?

Ans: An unborn offspring that develops and grows inside the uterus (womb) of humans and other mammals.

Q3: What is meant by congenital disease?

Ans: Congenital disorders can be defined as structural or functional anomalies that occur during intrauterine life. 

Source: TH

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