The “fetus in fetus” is a very rare birth defectwhich occurs only in cases of monozygotic twin pregnancies, when one of the twins grows inside the other. About one in 500,000 newborns is affected by this anomaly, according to a study published in the Hong Kong Medical Journal in 2015.
In the case of this little girl, the parents took her to the hospital because she suffered from an enlarged head and motor problems. Doctors then discovered the fetus of his twin within his brain. Healthcare professionals explained that the fetus had developed upper limbs, bones and even fingernails, and was about 15 centimeters long. CT scans revealed that the fetus was pressed against her sister’s brain, causing a hydrocephalusan accumulation of fluid in the brain that can be responsible for an enlarged head, extreme drowsiness and epileptic seizures (source 1).
Increased risk and a delicate operation
However, doctors pointed out that the baby girl was able to survive thanks to the blood supply she shared with the fetus. The two were connected by an umbilical cord that passed through the wall of the girl’s skull and reached her twin’s fetus. Doctors surgically removed the fetus from the girl’s skull while she was hospitalized, and shared images of the scans before and after the operation in the scientific article. The little girl is doing well and is recovering well from the operation.
The “fetus in fetus” remains a rare congenital malformation that is often difficult to diagnose. Cases detected before birth can be treated with prenatal surgery, while cases detected after birth usually require surgery to remove the fetus. Doctors encourage parents to monitor their children’s growth and development closely and to seek medical attention if any abnormalities are found.