Mono/Di Twins

Hi Everyone

Okay I am totally confused and ned this explained to me. When we had our initial sonogram when the babies were 6 weeks, they could not find 2 placentas they only could see one, but told me that there very well could be two but they just weren't seeing them right then at that time they also said they could not see a defined membrane dividing two sacs. When I got my down sydrome testing around my 11th week and had the ultrasound, the tech found a hairline membrane or what she believed it to be a hairline membrane and two placentas. Each time I was recorded as being mono/di and that each tech had they recorded not membrane or they could not find a defined membrane. SO... I had my 20 week ultrasound today - 2 GIRLS yeah!! During the ultrasound she said the placenta was in the back and that she thought she saw 2 but it could be one since she could not see it accurately and as she studied it from different angles she could not tell if t was one or two. Also for about 30 minutes she could not find any membrane separating the two girls. She finally saw a hairline membrane and said they could still be one sac and it might one placenta or two, because the placentas are in the back.

What am I confused about how am I mono/di, more specifically what does that mean? She said in her experience mono/di means identical, does that sound correct? I've been researching that mono/di means two sacs-one placenta, but from everything I've been told they are thinking one sac possibly two, maybe one or two placentas.

I was also told that unless they see otherwise they are going to treat this pregnancy mono/di....so are they meaning two sacs one placenta? also what does mono/di mean for me?

When I had my last set of twins - it was a defined gap between the two sac and two define placenta.

I'm confused... what does this mean?

 

Di/Di - two placentas, two sacs
Mono/Di - one placenta, two sacs
Mono/Mono - one placenta, one sac

If they are treating you as mono/di they are saying that there is one placenta and a membrane between the babes. My boys were mono/di and we only got a glimpse of the membrane - extremely thin, about once per u/s and it was searched for hard.

The biggest risk of mono/di that always comes up is twin to twin transfusion - where one twin receives all the blood, the other donates all the blood (just for simple definition sake) I honestly have no knowledge about how common it is - I stayed far away from Google and just went with my regular u/s (altho I DID panic that i didn't have enough of them). There are lots of moms here that could give you more info tho.

the fact that they say they've seen the membrane is good - mono/mono is not good as that means both babes are in one sac and can get tangled in cords. A glimpse is good enough to reassure you at this stage as sometimes thats all you get.

And yes - that would also mean they are identical!

 

there is also the chance that the two placentas have fused into one - hence the reason they are not sure. The fact that the membrane is soooo thin tho definitely is one thing that leads to the thought they are monochorionic, diamniotic.