I would recommend 'sitting' with the decision to use DE for a month or two, keep the communication channels open with DH, and also consider the implication for that potential child. They may or may not have full genetic siblings elsewhere in the UK and although I have limited knowledge of these matters I have given it some thought. I think DCN sounds like it is a great resource to tap into, I understand they link with families and also have conferences including DC children and their perspective. I read Olivia's blog every so often, she's (I think) one of the founders of DCN, or at least somewhere in the machinery, and thats given me some extra insight into these things.
Our story: male factor issues found after a couple of miscarriages, first IVF didn't work (using DP's sperm). We then used donor sperm for the next IVF cycle, got pg with Miss now21 months and also got 3 embryos for the freezer. As I can't imagine we will replace all 3 (2 kids would be our max) I gave some thought to donating the embryos on, and the implications for that child as well as DD. Initially the thinking was all about DP and I and what we could do with the extra embryos, yet this affects more than just us 2. How will DD feel knowing that she could have a brother or sister out there, and how would that unknown child feel, knowing they weren't the first to be chosen, that they weren't the best blastocyst in the mix (I know initially they wouldn't have that level of comprehension about it)
A friend who was also going through IVF same time we were seemed to have similar results to yourself - 3 cycles and none of the embryos really progressing. They had both male and female factors . . . used donor sperm on one last chance IVF and she is now pg.
Not sure why you would choose DE over DS, depends on how you both feel about full/partial/no genetic link. I wholeheartedly would endorse 2-3 counselling sessions to just talk through the whole thing with someone experienced with donor conception too. I found that really useful, just getting it out there, fears, concerns, how and when to tell the child about their genetic origins, that sort of thing.
Your mum's reaction sounds pretty cold. Is she worried about what people might think? People do try and look for who the baby takes after, I just smile and say 'do you think so' or 'I have no idea who she looks like', which is true!!? Does your mum have to know the details of conception? I am all about transparency, and we told our families what we were doing with the thinking that if any of them were going to have the sort of reaction your mum has, they could deal with it and move on quicksmart before the baby is born. But honestly, the genetic side of it does fade once you're parenting. Its always there in the background, but definitely not forefront