Megacystis 12 week scan

[37L]

Advice needed: at my 12 week scan I sadly found out that our baby’s bladder was 18mm and he has megacystis. After seeing a fetal professor he informed us that it has backed up to one of his kidneys and would cause further problems. With heavy hearts we have decided to end the pregnancy. I’d like to know if anyone else has been through this and if it reoccurred in future pregnancies? From the literature, I can’t seem to find out if this is something that is genetic. We had a harmony test at 12 weeks which was all clear and the professor said it was not linked to Trisomy 21 or 13 but has said it’s most likely a blockage of the valve in the urethra but I want to know if this could happen again and if anyone else has had this and gone on to have normal pregnancies?

Hi 37L
Im sorry to hear about your scan. It’s so stressful when something like this happens.
I had something similar in my 2nd pregnancy discovered at 16 weeks. We hoped the megacystis would resolve however it got progressively worse. We had full genetic testing and the abnormalities were due to a genetic change in a particular gene which caused a rare syndrome called Berdon syndrome or MMIHS. We only had the results of this after we had a termination at 25 weeks. This was a ‘de novo’ mutation so neither my husband or I carry the gene and we have a healthy older child.What happened to us is very rare but I know that megacystis can be caused by something called PUV which can be treatable. Please DM me if you have any questions

Thank you so much for your advice. Very comforting to know you went on to have a healthy child. Did they do the genetic testing as standard or did you pay to do this privately?

Thank you so much for your advice. Very comforting to know you went on to have a healthy child. Did they do the genetic testing as standard or did you pay to do this privately?@YellowVelvet111

Hi we got the genetic test on the NHS however they did have to discuss with a genetics team before offering us the testing. The doctors in fetal medicine thought out it was just a physical obstruction at first. Our baby was a girl thought and PUV is nearly always boys so they were sure it wasn’t that. Have you been referred to fetal medicine?
I know how hard it is. I don’t usually talk about this but I remember frantically googling and not really finding any answers online.

Hi OP. My daughter is currently going through this exact same thing.
She had an amnio and it's not chromosomal so purely structural. Initially prognosis wasn't great, but now it's very positive.
She would have terminated if chromosomal but as it isn't she's continuing the pregnancy.
Baby has one working kidney and a septate bladder, but overall prognosis is now good. Fee free to PM me if you want to chat, as I did so much research into this.

Thanks for your message. How far in to her pregnancy did it develop? Do you know what size the babies bladder is? The professor advised us that he didn’t think that the lungs would form properly due to the lack of amniotic fluid and that he’d probably have renal failure, sadly so we weren’t as fortunate as your daughter.

@YellowVelvet111 yes, I’ve read it’s not very common in girls. We were referred to fetal medicine and I was fortunate to see a professor who is the head of fetal medicine as the hospital that I’m under is a university hospital specialised in maternity. He was pretty sure it was PUV. I’m going to email him to see if they will run genetic testing after my procedure to get more of an understanding.

PUV I think is normally not genetic but it is worth asking if they will do the testing. I’m pregnant again and all looks healthy so try not to be too worried about it happening again

That’s great to hear. Congratulations and thanks for getting back to me @YellowVelvet111