“An ultrasound of the 28-year old mother at six weeks suggested the twins were identical...”
At only six weeks they can tell this? From my old science books I thought they were still “fish” with “gill slits” at that stage.
It’s only until they are born that you are certain it was a human in there. /s
BTW - we have identical twins, but never had them tested as such. (It was obvious, and no real need to.) I’m guessing that a lot of (most?) twins never get tested, so perhaps this is more common than they think??
The article said that they looked at around 1,000 sets of genetic data from twins and didn’t find any others like this. That would indicate it’s pretty rare.
An ultrasound at six weeks is unusual in my experience. 15 weeks was more typical. I wonder if there were indications that something was wrong.
A single placenta and single amniotic sac with two embryos, indicate identical twins. Two amniotic sacs with an embryo in each indicates fraternal.
And just so everyone knows so you can argue with your Lib friends, babies are fully formed by 12 weeks gestation. From there on out, they simply grow. And there is a detectable heartbeat at 18 days gestation. Use those facts the next time your Lib friends refer to a baby in the womb as ‘just a clump of cells’.
I think that the twins are not optimal specimens of humans.
Baby girl and blood clot and lost arm then had ovaries removed because they were sub optimal.
Have no idea of cognitive ability.
Two heartbeats in one amniotic sack is 99.9999999% identical twins.
I remember a set of twins in my Jr high school, one boy and one girl. They were similar in appearance, same height, facial features, body shape, etc. Apparently identical but for their sex. That was 65 years ago.
I never met my grandmother's twin brother, but I have always assumed that they were fraternal twins.