Thank you VivaleBeaver - that's a really well balanced post, and is helping me to frame my thoughts. This is a huge post and a bit of confessional as I'm trying to get all my real feelings about this down.
I am really worried about the placenta accreta thing as my placenta is covering my old cs scar, but when I asked the consultant she said it was rare... I'm actually terrified that if I did manage to give birth naturally I might be whipped off for surgery under GA after the birth as the accreta would only be discovered at third stage labour and I think that fear will stay with me through the birth. I think that's why the sonographer, registrar and a friend who is a consultant anaethatist (sps) have all suggested cs as the best option. This is my last pregnancy - DH prob having snip...
On the other figures - I looked them up, not to challenge you, but just to make sure I had them straight in my pregnant brain:
I think the risk for depression is higher for vaginal birth (10.8 pc v 10.1 pc acc. NICE so small difference but have seen larger difference elsewhere). This also includes, I believe, EMCS in CS figures. I think the risk of thromboembolism (is this the same as DVT?) is around 0.04% - it's higher for a cs but still very low. The risk of haemmorhage is lower for cs (0.5% v 0.7%). The risk of post surgery infection is higher, so you should be given prophilactic antibiotics.
I'm also terrified of an EMCS as I know these can be awful and mine will be more complicated anyway due to low anterior placenta. I don't think I have a good chance of VBAC. It would be my first labour, I have an obese BMI, I'm advanced maternal age and the baby is 95 centile (with a 100 centile ac causing concern for shoulder dystocia) and I'm completely physically and emotionally unprepared (having never thought I'd go through a "natural birth").
Then there's the emotional issues which I know I need to start dealing with quickly if there's a possibility I may be forced to have a VBAC:
I'm terrified of birth trauma and have been all my life. To me vaginal birth is unnatural and disgusting - which I understand is wrong (and that is beautiful and empowering for many women), but feel at a really deep level.
When I had my boys my world fell apart completely and I felt utterly out of control. I lost all faith in medical professionals. The only thing that feels positive about the whole experience was the elcs itself and seeing my babies for the first time in that way. I had to draw on those few seconds over and over again to get through the first few months.
I also have struggled to come to terms with the effect of the first pregnancy on my body - my twins were huge and my abdomen is now deformed in my eyes. I haven't looked in a mirror at myself naked since the birth. My DH hasn't seen me naked and any intercourse is with me semi clothed with the lights off. If my vagina had been affected by the birth, I don't think we would have made it that far...
I'm going to phone the midwives tomorrow to ask to have an appointment with someone. I'm going to ask to have a different consultant, but also to see if I can be referred for counselling concurrently with the process of finding out whether I can get an elcs.