Vanishing twin

Angie and I watched this show on the Discovery Health channel called "Vanishing Twin". It seems that 1 in 8 pregnancies starts off as twins, but only 1 in 70 leads to the birth of twins. Most often, one of the fetuses fails to develop properly in the first trimester and is absorbed by either it's twin, the placenta, or the mother. But in some rare cases, the underdeveloped fetus ends up being engulfed by the healthy fetus and becomes a parasite. Almost like the baby having a baby inside it. The really creepy case they showed was in a third world country where a boy had his parasitic twin removed from his abdomen after 7 years! The twin was a fleshy ball with flipper-like appendages, no internal organs, an empty brain cavity, and a thick head of black hair about a foot long.

Disturbing? Hell yeah. But God do I love science shows.