A twin fetus is surgically removed from the SKULL of a one-year-old sister in China, after she went to the doctor with an enlarged head and cognitive problems.
A twin’s fetus has been surgically removed from the skull of their one-year-old sister, in a medical anomaly that has only been recorded a few times.
Doctors said the fetus had developed upper limbs, bones and even nails, meaning it likely continued to grow for months while it was inside its brother in the womb.
The fetus, which was about four inches long, was only discovered when the parents took their daughter for a scanner at the hospital because she had an enlarged head and problems with motor skills.
Fetus-in-fetu is the medical term for the rare phenomenon in which twins are fused together in the womb and one physically develops inside the other.
Only around 200 cases have been documented, of which only 18 occurred inside the skull.
The above shows a scan of the girl’s skull with the pictured fetus inside.
Doctors said the fetus had developed upper limbs, bones and even nails, meaning it likely continued to grow for months while it was inside its brother in the womb.
Fetus-in-fetu has also been detected in the pelvis, mouth, intestines, and even the scrotum.
The condition is caused by the incomplete separation of identical twins, which are formed when one egg cell divides. Doctors don’t know exactly how this happens.
Some have theorized that the healthy twin connects to the mother via the placenta, while the other attaches to the twin’s blood vessels.
As the larger twin grows, the smaller one is absorbed into its abdomen. Other scientists have suggested that it happens as a result of late cell division.
The nonviable fetus can continue to develop for several weeks and months inside its sibling, even forming organs, bones, and limbs.
The latest story broke in December in the Journal of the American Academy of Neurology. Neurology.
The unidentified girl was taken to hospital after showing problems with her motor skills.
The doctors did not elaborate, but this may include problems walking or sitting.
CT scans revealed that her unborn brother was pressed against her brain.
He also had hydrocephalus, the buildup of fluid deep in the brain that can cause an enlarged head, extreme drowsiness and seizures.
Doctors said she had continued to survive a year after birth because she shared her brother’s blood supply.
It was not clear if the surviving twin will suffer long-term damage.
Dr. Zongze Li, a neurologist at Fudan University Huashan Hospital who treated the girl, said: “The intracranial fetus is proposed to arise from unseparated blastocysts.”
“The attached parts develop in the forebrain of the host fetus and envelop the other embryo during the folding of the neural plate.”
The case is one of only 18 reported in the medical literature to date.
Doctors in Thailand in 2017, found three brothers inside the skull of an unborn girl.
They said each had “multiple well-developed organs,” including a nervous, digestive, and respiratory system.
They were connected to the host brother through a single artery and vein, which the doctors said had been the umbilical cord.
In another case from 2015Also in China, doctors found a fetus inside the scrotal sac of its male twin.
The 20-day-old baby was taken to hospital after birth when his scrotum began to swell.
Scans revealed a ‘well-defined…mass’ within the scrotum, complete with bones and buds that doctors say would have become limbs.
The fetus was surgically removed and her twin was discharged five days after surgery, having made a full recovery.
