Are our twins DCDA or MCDA?

Hello all
Hope you can help?
We are expecting twins. Anyhow, we are confused as to if they are DCDA or MCDA as at the first scan they said they were DCDA, the 2nd scan we were told they couldnt tell DCDA or MCDA and the 3rd scan we were told they still couldnt tell and will put down MCDA to be on the safe side. All of this was with the NHS
We also got a second opinion privatly and he said they are for certain DCDA NOT MCDA.
So we just dont know what to think for sure.
We have been looking at our scan pictures and in particular on the last ones, in our opinion and in others opinion the babies look VERY different from eachother. Totally different chins and totally different shapped skulls. So I presume that would indicate they are not identical.
DCDA Boy/Girls run in the family, but I dont know if DCDA Boy/girl twins are more likeley for us or just any type of "twins" wether DCDA, MCDA, MCMA?
Anyhow, here are our scan pictures if anyone can work out if they are unidentical meaning they are DCDA, thanks in advance all
or maybe what their genders might be even?
Heres 6 weeks 6 days
www.2imgs.com/dbe7c1eb38
www.2imgs.com/ac90b69c4f
and11 weeks and 2 days
http://2imgs.com/41bc7a5083
and 13 weeks 2 days
www.2imgs.com/8b6e5872a1

 

So, first off DCDA twins can be identical - it just means they started from one zygote but the zygote split early enough that each baby developed their own chorion (placenta) and amnion (amniotic sac). If your babies are the same gender, you'd likely have to get a DNA test after birth to 100% confirm their zygosity.

To determine whether your twins are mono or di chorionic, you need to look at placentas. Mono chorionic twins share a placenta. Di chorionic twins have separate placentas, but if the placentas implant in the uterus close together they can fuse as they grow which then makes them look like one placenta. I would ask your doctor what led them to change their diagnosis. It would seem to me that the earlier ultrasound would be the most accurate. And chorionicity is something you want to be as sure of as possible because the standards of care for DCDA and MCDA twins are very different.