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Identical twins are super interesting to researchers, because when studying the human body, it's really hard to get a control group. Even fraternal twins are i

Identical twins are super interesting to researchers, because when studying the human body, it's really hard to get a control group. Even fraternal twins are interesting to sociologists if they were raised in the same household, since for the most part they would have the same or very similar lived childhood experience.

KMag 3y ago
One thing I found out after my wife and I discovered we were having identical twins is that manipulation of embryos increases the odds of having identical twins. In our case, the embryos were frozen, thawed, a few cells removed for pre-implantation genetic testing, frozen, thawed, and implanted again. Two embryos were implanted, but only one took hold. Then the one that took hold decided to become two people.
- jedberg 3y ago
  When we did IVF we were warned of the same thing! In fact, when you see an older couple with young twins, it's a really good bet that they did IVF. :) (We ended up getting singles twice, but we like to tell people they started as twins until we cryogenically froze one of them for two years)
  - KMag 3y ago
    Fraternal twins are much more common than identical twins, because most IVF clinics will implant two embryos at a time, due to the chances of implantation failure. (Also, for non-IVF, fraternal twins are also much more common, for different reasons.)
    - jedberg 3y ago
      Our clinic offered a buy one get one free deal instead -- if the first implantation is unsuccessful, the second one is free, just to avoid that risk.
    - rrdharan 3y ago
      > because most IVF clinics will implant two embryos at a time This is very country dependent and is actually changing quite rapidly. I believe these days in the USA standard of care is single embryo transfer. It’s well known that twins are a much higher risk pregnancy: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5846681/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5846681/ FWIW when my wife and I went through the IVF process our provider (RMA, who are basically a large US-wide franchise) informed us that multiple embryo transfer was not an option offered by their clinic (not that we would have chosen it, but point is it wasn’t presented as a choice).
- klipt 3y ago
  Maybe it's a stress response. "One of my cells just disappeared! Better duplicate myself just in case"
js2 3y ago
Along that note, let me recommend Three Identical Strangers: https://en.wikipedia.org/wiki/Three_Identical_Strangers https://en.wikipedia.org/wiki/Three_Identical_Strangers
- yboris 3y ago
  Thank you for the recommendation!
curiouser2 3y ago
Greg Egan's book Axiomatic has a short story "Blood Sisters" around the medical implications of twins, interesting read

KMag 3y ago

One thing I found out after my wife and I discovered we were having identical twins is that manipulation of embryos increases the odds of having identical twins. In our case, the embryos were frozen, thawed, a few cells removed for pre-implantation genetic testing, frozen, thawed, and implanted again. Two embryos were implanted, but only one took hold. Then the one that took hold decided to become two people.

jedberg 3y ago
When we did IVF we were warned of the same thing! In fact, when you see an older couple with young twins, it's a really good bet that they did IVF. :) (We ended up getting singles twice, but we like to tell people they started as twins until we cryogenically froze one of them for two years)
- KMag 3y ago
  Fraternal twins are much more common than identical twins, because most IVF clinics will implant two embryos at a time, due to the chances of implantation failure. (Also, for non-IVF, fraternal twins are also much more common, for different reasons.)
  - jedberg 3y ago
    Our clinic offered a buy one get one free deal instead -- if the first implantation is unsuccessful, the second one is free, just to avoid that risk.
  - rrdharan 3y ago
    > because most IVF clinics will implant two embryos at a time This is very country dependent and is actually changing quite rapidly. I believe these days in the USA standard of care is single embryo transfer. It’s well known that twins are a much higher risk pregnancy: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5846681/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5846681/ FWIW when my wife and I went through the IVF process our provider (RMA, who are basically a large US-wide franchise) informed us that multiple embryo transfer was not an option offered by their clinic (not that we would have chosen it, but point is it wasn’t presented as a choice).
klipt 3y ago
Maybe it's a stress response. "One of my cells just disappeared! Better duplicate myself just in case"

js2 3y ago

Along that note, let me recommend Three Identical Strangers: https://en.wikipedia.org/wiki/Three_Identical_Strangers https://en.wikipedia.org/wiki/Three_Identical_Strangers

yboris 3y ago
Thank you for the recommendation!

curiouser2 3y ago

Greg Egan's book Axiomatic has a short story "Blood Sisters" around the medical implications of twins, interesting read