Hi Sarah,
I've recently been through this. I'll tell you what happened to us.
At the 20 week scan my baby's bowel showed up bright so we were referred to our local fetal medicine unit to see a consultant. A week later we went and he scanned us again and confirmed the baby's bowel was echogenic.
Both DP and I had blood tests. I had TORCH infection screening and a check for cystic fibrosis carrier status and DP had CF carrier testing too. I assume this is what you've had done too?
My TORCH (toxoplasmosis, Rubella, Cytomeglavirus and Herpes) screen came back clear, DP's CF screen came back clear but my CF screen came back showing I was a carrier of a mutant gene (I had no idea of this, no CF in my family and I already have a DD and there was never any worry over her). The standard test looks for the 50 most common mutations of the CF gene (which account for about 90% of the cases of CF in the UK). However, there are over 1800 known genetic mutations of the CF gene.
We were told, considering my carrier status and our baby's echogenic bowel, that our baby had a 1 in 20 chance of having cystic fibrosis. Obviously we were pretty devastated by this statistic. We saw a genetic counsellor who was very helpful and offered us further testing. We opted to have DP's entire CF gene looked at to establish if he had any faults in his CF gene at all. As CF is a recessive, inherited condition both my DP and I would have to have faulty genes to give our baby a 1 in 4 chance of having CF (1 chance of inheriting my faulty gene but DP's good gene and therefore being a just carrier like me, 1 chance of inheriting my good gene but DP's potential bad gene and therefore being a carrier like me, 1 chance of inheriting both my faulty gene and DP's potential faulty gene and having cystic fibrosis and 1 chance of inheriting both non-faulty genes therefore having neither CF or being a carrier).
We waited probably the longest the 2 weeks of our lives for those results. It was incredibly stressful, it was Christmas, I was 26 weeks PG by this stage and was being asked questions like "Will you want to continue with the PG should your partner's results come back with a finding of a rare mutation?" "Do I understand ending the PG at this stage will mean giving birth to the fetus?"
It was horrible.
Thank God/The Godess/Mother nature/Karma, whatever you believe in, DP's results were completely clear, his CF gene has no faults at all. It would take a spontaneous mutation in the one sperm which made it to the egg for our baby to have CF. In other words a one in a million chance.
We saw the consultant again at 31 weeks and the baby's bowel was no longer echogenic. The consultant put it down to most probably having been a small bleed, which I hadn't noticed, the baby swallowed some and it had shown up in the bowel at the scan. He said he sees 5+ echogenic bowels a week and in all the years he's been doing this only a few have turned out to be anything dodgy.
I don't know if this is reassuring for you to read but I thought I'd share (and maybe debrief for myself too!). It's about the most stressful and worrying things you can experience; something being potentially 'wrong' with your baby. I know exactly where you are right now, I was you a few months ago. I felt that I wanted to ignore the baby until I knew he was OK. I stopped buying stuff for him and tried to stop making plans, just in case. I tried to keep positive, I tried to look at the figures and tell myself the chances were incredibly slim but because there was still a chance I couldn't allow myself to relax and enjoy my pregnancy. From week 20 to week 28 it was awful and weeks 28 to 31 whilst better than the previous 8 weeks, were still stressy because if CF wasn't causing the echogenicity then what was and was it still there?
It sounds like your hospital is moving faster than mine did, booking you in for an amnio before you've had your blood results, which is good, really good. The waiting and not knowing is the worst.
I wish you the very best of luck, I truly, truly hope your baby is OK and you get good news soon, really soon.