In China's Shanghai, an 'unborn twin' was discovered in the brain of a one-year-old child, as per a study in the journal Neurology. The discovery added to the very few cases of a condition known as 'fetus-in-fetu,' in which twins become conjoined in the mother's womb but only one of the two develops.
The study said that the child was brought to the hospital after displaying motor function issues and an enlarged head. The twin's developing foetus was discovered by doctors inside the host child's brain. The study added, "An intraventricular fetus-in-fetu, a malformed monochorionic diamniotic twin, was identified in a 1-year-old girl with motor delay and enlarged head circumference." Furthermore, a genome scan revealed that the foetus was the child's twin.
The term 'parasitic twin' is also used to describe the condition. Such cases start to appear during the first trimester of pregnancy, according to a report in IFL Science. It happens when a group of cells that form as a result of the fertilisation of a female egg and a male sperm fail to split properly. Following this, one of the young embryos is enveloped by the other. It fails to develop while encased by the other twin's replicating cells, but it remains "alive" due to the blood supply.
The study further mentioned, "The conjoined parts develop into the forebrain of host foetus and envelop the other embryo during neural plate folding."
However, this is not the first time such an incident has taken place. An Egyptian teenage boy's abdomen contained a foetus that had been there for 16 years when it was found there in 1997. Not only this, in November last year, eight embryos were removed from the stomach of a 21-day-old infant in Jharkhand's Ranchi.
