Hell, even for conjoined twins, the odds for survival are so astronomically low that the number of living twins that currently exist probably doesn't need all your fingers and toes to count them.Fun fact: What you're referring to here actually has a damn close match in the case of a parasitic twin, a variation of the conjoined twin in which one effectively stops developing in utero and as such lacks an independent consciousness. To put it simply, it is functionally vestigial. Consquentially, the parasitic twin is not considered an independent person and tends to be surgically removed from the autonomous twin shortly after birth.
The exact situation tstorm proposed happened in Britain in 2000 and as the situation was going to invariably kill the both of them, the courts overrode the parent's objections and saved the stronger child
We don't know how to tell Gracie her sister died so she could live; EXCLUSIVE DILEMMA FACING TWINS' PARENTS DAILY Mirror BEST FOR REAL LIFE. - Free Online Library
Free Online Library: We don't know how to tell Gracie her sister died so she could live; EXCLUSIVE DILEMMA FACING TWINS' PARENTS DAILY Mirror BEST FOR REAL LIFE.(News) by "The Mirror (London, England)"; General interest
www.thefreelibrary.com
Life's messy like that.