The unusual pregnancy was not a pregnancy at all, but an extremely rare condition, so rare, in fact, that only 200 cases have been documented in the world. Fetus-in-fetu is a developmental abnormality. In this case, something went wrong and two of the three fetuses were absorbed into the one remaining fetus.
“Weird things happen early, early in the pregnancy that we just don’t understand,” said Dr. Draion Burch, an obstetrician and gynecologist in Pittsburgh, who goes by Dr. Drai told Discovery News. “This is one of those medical mysteries.”
The mother of the nine-pound baby girl is thought to have been pregnant with triplets, but for some unknown reason, the baby girl interred her siblings within her own body. According to Dr. Yu Kai-man, a specialist in obstetrics and gynecology at Queen Elizabeth Hospital in Hong Kong, the two fetuses each had “four limbs, a spine, rib cage, intestines, and anus, but were different in weight. The twins weighed 14.2 grams and the other 9.3 grams, and each had an umbilical cord connected to a single placenta-like mass.”
According to the case report, published in the latest edition of the Hong Kong Medical Journal, the woman’s prenatal ultrasound had revealed an unusual mass within the developing infant. It was unclear at that time what the mass could be. During surgery, doctors found the fetuses wedged between the baby’s liver and her kidney.
According to the World Health Organization, fetus-in-fetu is classified as a variant of mature teratoma, a type of cancer. There is another theory, called, “‘monozygotic diamniotic twins.” In this theory, one twin dies and the living fetus absorbs its twin into its own body. But according to the case report, the doctors said: “Our case report does not support the popular monozygotic multiple pregnancy theory, and favors, by default, the traditional classification into a teratoma.”
