The primary concern for the prospective parents when an isolated marker of dilated renal pelvis is found is kidney function. There is, of-course, no immediate concern with the baby in the womb. However, many experts advocate a repeat scan later in the third trimester to see if the dilatation is persisting (many do not). If persistent dilatation is found, a paediatric specialist is alerted so they can take over when the baby is born.
The majority of babies found to have mild renal pelvis dilatation will need nothing more than observation and the problem resolves spontaneously. A few, usually those with moderate or severe dilatation, may need surgery for either some element of obstruction at the junction of the kidney and ureter (Pelvi-ureteric junction) or reflux of urine from the bladder up the ureter, a condition known as Vesico-ureteric reflux (VUR). These are structural anomalies which are uncommon and certainly not associated with chromosomal disorders.