The mother was 35 weeks along when advanced ultrasound imaging was used to investigate a suspected liver cyst in her fetus. It turned out to be something else entirely: a baby within a baby, a twin within her twin. The Colombian case of "fetus-in-fetu," described by the New York Times, is highly rare, believed to happen in just one in 500,000 births. Diagnosing it during pregnancy is even rarer still. The doctor who did so, Dr. Miguel Parra-Saavedra, says the imaging allowed him to see that what he expected to appear as a cyst was in fact a much smaller fetus who had an umbilical cord of its own that attached to the intestine of the larger fetus.
The 33-year-old mom gave birth to a daughter named Itzamara via C-section two weeks later, over fears the girl's abdominal organs were being squashed by what Parra-Saavedra says was her identical twin. That two-inch twin was removed using laparoscopic surgery the following day. Parra-Saavedra said there was no brain or heart though a head and limbs were discernable. Read the full Times article for more on how the doctors believe the condition occurs. (An unborn twin was removed from a 15-year-old in 2016.)