Do you know that pyelectasis (Renal Pelvis Dilatation) is an abnormality that could be found in a baby while she is still residing in her mummy’s womb? It is the dilatation of the renal pelvis, or the part of the kidney from where the urine pipe (ureter) starts. It signifies the soft marker of chromosomal abnormalities. Chromosomes determine the genetic makeup of an individual. Soft marker is something which alerts the doctor of possibility of chromosomal problems in the baby. If a baby is diagnosed to have pyelectasis, she has 1.6 times higher chance of having Down Syndrome. The more soft markers are detected in the baby, the higher the risk of Down Syndrome would be.

If the pregnant mother whose baby has pyelectasis is 36 years or older, the baby she carries has 2.2% chance of being Down Syndrome. If the expecting mother is younger than 36 years old, then the chance of her baby being Down Syndrome is only 0.33%. Thus, older expecting mothers would be recommended to undergo amniocentesis (aspiration of the amniotic fluid) to confirm the baby’s chromosomes. Normally is it found on Foetal Anomaly Scan (FA Scan) done between 18 and 23 weeks to check the normality of the baby’s different organs. However, if FA Scan is not performed, it may be just by chance during the routine ultrasound scanning that it is detected.

If the pelvic dilatation is between 4 and 7 mm, it is considered mild. 80% of such cases would resolve by itself before birth. 17% may only resolve to normal after birth and 3% of cases would need long term follow-up. If the dilatation is more than 7 mm, then only 44% may resolve, usually after birth. The rest may have urinary problems like obstruction or reflux (back flow of urine upwards). These cases would need to be further assessed after birth with ultrasound scan, as well as a voiding cystourethrogram, a test used to visualise the urethra and urinary bladder that takes place during micturition (voiding).

From: Parenthood Magazine May 2008