Looks like science fiction, but true.
Molly and Emma are genetic siblings. Emma was thawed first; Molly few years later, had been frozen for 27 years.
Picture of the girls: https://www.zerohedge.com/s3/files/inline-images/molly%20emma.PNG?itok=EDyreJmh
Following URL gives some details: https://www.zerohedge.com/political/knoxville-embryo-reanimated-after-quarter-century-record-breaking-live-birth
A few cells, soon after fertilization, is frozen: can be frozen for 27 years: care and a womb can result in a healthy baby.
What happens with the unused frozen embryos?
My vector to the URL started at Voat.co
Is it ethical to choose to bring twins to maturity by others, having selected for characteristics
OR to knowingly bring to maturity one's own twin who would have identical organs?
'Hanna' is about gene manipulation; 'Soldier' is about selection; 'Boys from Brazil' is about cloning a known person.
There are sci-fi about cloning for organ harvest.
I don't know of a sci-fi: a society where parents freeze twin embryos so that a child later can choose to develop a frozen twin for organ harvest.