Fetal Renal Pelvic Dilatation

Hello, we had our 20 week u/s and apparently one of our bubs kidney (right kidney) has fetal renal pelvic dilatation (4.3mm). Ultrasound lady didnt seem too concerned and said all other measurements were great, and really not to stress, and that generally this fixes itself in utero.
I have red a bit on the net and have not been able to find much about this.
U/S lady said that I have to go back at 30 weeks for another ultrasound with them, and that if she were really concerned they would be sending me to their u/s doctor, so not to stress.
Sorry for the rambling, I just want to know if anyone else has had this picked up on their scan and what was the outcome? Also if anyone knows is 4.3mm something to be concerned about? Other kidney measurement was great.
Hoping for some replies to ease my mind.
Thanks in advance

Anyone???

Hi Mummy2one,

My DS is 5 years old. He was diagnosed with severe renal complications at the 20 week US. My DS has an absent left kidney and many complications with his solitary right kidney. He was diagnosed with a dilated renal pelvis on US, I'm sorry I can't remember the measurement! A dilated renal pelvis is usually indicative of hydronephrosis - the urine pools in the renal pelvis rather than draining directly into the bladder. The kidney is at risk of damage by the pressure the urine exerts on the kidney and is also more prone to infection once bub is born. Having said all of that, the sonographer is correct - a dilated renal pelvis at 20 weeks gestation will *usually* correct itself by the time bub is born. The measurement is variable from hour to hour as it depends on how full the bladder is. Even if your bub has a dilated renal pelvis at the time of birth, or hydronephrosis of that kidney, it may improve or correct itself over the first year or two of bub's life as the kidney grows and develops. The best news is, your bub has another perfectly healthy looking kidney which is very capable of doing the job on it's own (not that a dilated renal pelvis indicates a non-functioning kidney!).

As difficult as it is, try to relax and enjoy your pregnancy. I truly hope that by the time of your next US your bub's renal pelvis has corrected - but even if it hasn't your baby will still be fine.

Hey hun

My last little man had the same thing show up at 19 weeks. His was bilateral though. Measurements were the same as yours from memory.
My understanding was that this can be a fairly common finding, which often resolves during the rest of the pregnancy. You're right, another ultrasound is performed. We had a repeat one done at 30 weeks which showed everything looked normal. So don't worry!
I think they used to give antibiotics to some of the babies who showed this in utero, but apparently recent studies in the last few years shows that this is probably not needed. Sometimes they might also like to do an ultrasound after the baby has been born to check again, but if the problem seems to have resolved there's no real need to do that either. Just keep an eye out for any signs of an infection etc.

Our paed decided initially there was no need to do an ultrasound after he was born, but we ended up having one a few weeks ago only because our fella has another health problem and has been having everything checked out.

I'm sure everything will be all fine with your little one. All the best!

Mummy2one, I have no advice on the fetal side of renal pelvis dilatation but my DS does have the condition. It was initially picked up when he contracting an UTI not long after being discharged from SCN and was readmitted due to the severity of the UTI.

His left renal pelvis measures 3.9mm and right 1.6mm. The measurement and UTI were initial flags that he may have renal reflux or a blockage but tests confirmed that this was not the case. His paediatrician is not at all concerned as the measurement is not more than 10mm. He does have an u/s every 6 months to confirm that there is no increase in size. I have been advised that a decrease in size is expected (in the majority of cases) as the issue usually resolves itself with time.

:hug: Hun, I know it's difficult not to worry but bear in mind the majority of cases do resolve themselves in utero or shortly after birth and there is treatment if reflux or blockage is found to be the cause.

Sending H&H vibes to you & bub.