This abnormality caused by errors during morphogenesis, the biological process that causes an organism to develop its shape. There are two theories of origin concerning fetus in fetu. One theory is that the mass begins as a normal fetus but becomes enveloped inside its twin. The other theory is that the mass is a highly developed teratoma. Fetus in fetu is estimated to occur in 1 in 500,000 live births.
Male pregnancy refers to the incubation of one or more embryos or fetuses by the male of any species. Almost all pregnancies in the animal kingdom are carried by female organisms. In all heterogamous species, the males produce the spermatozoa and rarely, if ever, host the zygote (the pipefish and seahorse are notable exceptions). Fetus in fetu is one of the reasons of the same apart from sex change being the other one.
notable Cases of fetus in fetu:
- Alamjan Nematilaev was the surviving host of a fetus in fetu. In 2003, aged 7, his school physician in Kazakhstan referred him to hospital after movements were detected in the boy's enlarged stomach. An operation intended to remove a cyst uncovered the fetus of Alamjan's identical twin brother, which had lived as parasitic growth inside the boy throughout his entire life. The fetus was comparatively highly developed, with hair, arms, fingers, nails, legs, toes, genitals, a head, and a vague approximation of a face.
- In June 1999, the case of Sanju Bhagat a man from Nagpur, India attracted attention for the length of time (36 years) he had carried his parasitic "twin" inside his body, and the size of the growth. As Bhagat had no placenta the growth had connected directly to his blood supply.
- In March 2006, Doctors in Pakistan removed two fetuses from inside a two-month-old baby girl.
- In November 2006, a Chilean boy in Santiago was diagnosed with fetus in fetu shortly before birth.
- In August 2007, a two month old baby in Baguio from the Philippines named Eljie Millapes was diagnosed with fetus in fetu. The parents of Eljie Millapes were alarmed by the abnormal growth of the stomach of their two-month-old baby. Doctors later discovered that she was suffering from fetus in fetu.
- In January 2008, a two-month-old baby in Medan, Indonesia named Afiah Syafina was diagnosed with tumor in her stomach. After the operation was done at January 19, 2008, the results were startling enough. The suspected tumor was a five-month-old fetus.
- In May 2008, a two-inch (5 cm) embryo was removed from the belly of a 9-year-old girl at Larissa General Hospital in Athens after she was diagnosed with a tumor on the right side of her belly. The embryo was a fetus with a head, hair and eyes, but no brain or umbilical cord.
- In October, 2008, a doctor in the USA removed a brain tumor that consisted of a foot and other body parts. This may have been a case of fetus in fetu or it may have been a teratoma.
- At some date during 2005 to 2008, an 8-pound, 13-inch baby, Waylan Kleinman, was born with a small abdominal mass. Two days after he was born, Waylan was operated on. Surgeons soon discovered a small orange-sized fetus that was documented as actually showing movement on ultrasound, a first for a fetus in fetu.