Currently most pregnant women undergo one or two ultrasound scans during their pregnancy. When the fetus is scanned, kidneys and the urinary tracts are analyzed, In addition the volume of liquor (amniotic fluid) also helps to suspect kidney problems. Of late stretching of the kidney (Hydronephrosis) is detected very frequently.
- Kidney Stretching (Hydronephrosis)
- Single Kidney Stretching (Unilateral Hydronephrosis)
- Both Kidneys Stretching (Bilateral Hydronephrosis)
- Consultation before birth (Antenatal Counseling)
Kidney Stretching (Hydronephrosis)
During scanning of 100-200 pregnant ladies, one fetus is found to have this abnormality. This usually happens because of a blockage in the urinary tract. Before proceeding further it is essential to describe the normal arrangement of the kidneys.
In human body there are two kidneys, one on either side of belly. From each kidney urine drains out via a tube called ‘ureter’ into a common urinary bladder. The bladder is located in the lower most part of belly. Once enough urine accumulates, it empties via a tube called ‘urethra’. Whenever there is a block in any of these tubes, kidney stretching results.
Single Kidney Stretching (Unilateral Hydron)
When only one kidney (right or left) stretches, blockage is suspected only on that side. When kidneys only stretch, the blockage is suspected at a higher location (PUJ obstruction). When the pipe draining the kidney also stretches, blockage is suspected at a lower location (VUJ obstruction).
Newborns with this problem need to be scanned on the third day after birth. In general very mild stretching is likely to settle spontaneously. Huge stretching requires surgery urgently to prevent loss of kidney function (renal failure). Children with moderate stretching need close monitoring with repeat scans and further tests. It is essential to consult a pediatric urologist to determine what tests are required and when a surgery could be avoided. Also it is essential to prevent urinary infection by taking a small dose of antibiotic once at night.
Both Kidneys Stretching (Bilateral Hydronephrosis)
When both kidneys stretch, they can be blocked separately. But usually they are blocked as urine exits the bladder in the ‘urethra’. In boys a valve like blockage can result in stretching of both kidneys (posterior urethral vale – PUV). Immediate endoscopic intervention after birth is essential to prevent urine infection and kidney failure.
Consultation before birth (Antenatal Counseling)
When there is a fetal kidney problem, there could be a lot of anxiety among parents. Consulting a paediatric urologist can relieve the anxieties and also provide answer to many questions. It will help to plan the type of delivery, place of delivery (where the treatment is available to the baby after birth), the type of tests required after birth. Also it helps to find out more about what is expected in the long run (prognosis) and whether the problem can occur again in future children (familial incidence).
Key Points:
- It is possible to determine kidney problems in the baby before birth.
- Most of the kidney problems correct spontaneously, although it is essential to confirm this by consulting a Paediatric Urologist
- A small proportion of babies require corrective surgery after birth.
- By consulting before delivery, parents can relieve their anxieties.