di-di, mz, gt, etc

[pedi08]

i'm new here, having trouble following some of the discussions... what is a gt test? what is di-di, dz and mz? anything else?

[hergrace]

Originally Posted by pedi08

i'm new here, having trouble following some of the discussions... what is a gt test? what is di-di, dz and mz? anything else?

mz - monozygotic (from one egg)
dz - dizygotic (from two eggs)
tz - trizygotic
gt- glucose tolerance
di-di - dichorionic, diamniotic
mono-di - monochorionic, diamniotic
mono-mono - monochorionic, monoamniotic

[pedi08]

Awesome, thank you! Know I'll go google all of those!!!!

[Gena 22]

GT = Glucose tolerance test, for gestational diabetes (which is called GD sometimes)

di-di = dichorionic-diamniotic, which means the twins have separate everything in utero. The other configurations are mono-di = monochorionic-diamniotic, which only occurs with monozygotic = mz twins. These are also known as identical twins. Fraternal twins are dz = dizygotic.

Only MZ twins that share a placenta can get twin to twin transfusion syndrome = TTTS.

Hope that helps!

[DoomaYula]

The easiest way for me to remember is that DZ twins are always dichorionic/diamniotic. They come from 2 eggs, so there's always 2 chorions and 2 amnions (one for each egg).

When it comes to MZ twins, it's a little more complicated, but I really like this picture for explaining it.

It says that among MZ twins, mono/di is the most common, and I'm not sure if that's true. But that is what mine were.

MZ mono/mono is very rare and the most difficult for a pregnancy because of the risk of cord entanglement.

If twins are di/di and the same sex, there's no way to know if they're MZ or DZ until they're born. And even then, some DZ twins can look really alike.

As far as "riskiness" of pregnancy, I'd feel comfortable homebirthing with di/di twins (either MZ or DZ); MZ twins who are mono/di are at risk for TTTS so I'd maybe homebirth only if I were also seeing a Ob regularly for TTTS checks; and MZ mono/mono are very risky and usually delivered by scheduled c-s around 32w (or earlier) because of the risks I mentioned.

Someone correct me if I'm wrong; I used to know this stuff really well but now my twins are almost 8!