A Colombian baby girl has undergone surgery to remove her partially developed twin brother from her abdomen, an extremely rare condition known as fetus in fetu (FIF).
The medical literature reports that FIF is a "rare anomaly of embryogenesis in which a malformed parasitic twin is found within the body of the normally developed host."
According to the British Medical Journal, it occurs in just one in 500,000 births. But while most cases present as an abdominal mass during the first year of life, what made this case unusual is that it was discovered pre-natally.
High-risk specialist Dr. Miguel Parra-Saavedra told the New York Times that he initially saw mother Monica Vega when she was 35 weeks pregnant due to concerns her unborn baby may have developed a cyst in her liver.
When Dr Parra-Saavedra examined the 33-year-old via 3D/4D ultrasound, he discovered that the fluid-filled space wasn't a cyst: it contained a tiny, partially developed baby with a separate umbilical cord attached to his twin's intestine.
"I told the mother and she said 'what? No, doctor this is impossible," Dr Parra-Saavedra told the New York Times. "But I explained step-by-step and she understood."
After the diagnosis, local television station Los_Informante followed Ms Vega through the birth of her daughter, Itzamara and subsequent surgery to remove the fetal twin.
Doctors made the decision to deliver Itzamara via c-section on 22 February at 37 weeks, due to concerns that her twin would crush her abdominal organs.The twin, who measured just five centimetres, was removed the following day via keyhole surgery.
According to Dr Parra-Saavedra, he had a head and limbs but no heart or brain and died after the umbilical cord was cut.
"[It's] one of the strangest and most fascinating things that are seen in maternal-fetal medicine," he told local paper El Heraldo.
Baby Itzamara is now recovering well.
"She has a little scar on her abdomen, but she is a normal baby now, except that the whole world is talking about her." Dr Parra-Saavedra said.