Q. Is it possible to diagnose kidney problems before the child is born and which are the problems that can be identified?

A. Yes. Diseases of kidney like hydronephrosis i.e. large kidneys because of dilatation of pelvis, calyces with or without dilatation of ureters due to obstruction at pelviureteral junction or vesicoureteral junction, posterior urethral valves etc can be diagnosed after 18-22 weeks of pregnancy. Complete absence of one or both kidneys i.e. agenesis or small poorly developed kidneys i.e. hypoplastic / dysplastic kidneys can be detected antenatally. Diagnosis of congenital defects of both kidneys like polycystic disease or multicystic disease is also possible.

Q. How do you diagnose renal diseases antenatally ?

A. Diagnosis of renal problems is possible by ultrasonography of kidneys of the unborn child serially from 18th week to 30th week of pregnancy. Evaluation of amount of amniotic find which surrounds the baby is indirect method of estimating the quantity of urine passed by the baby since 50% of amniotic fluid is constituted by fetal urine. Analysis of fetal urine obtained by tapping the bladder under USG guidance is one of the recent advances in measuring renal function of fetus. Chromosomal analysis of amniotic fluid helps in diagnosis of defects with syndromes.

Q. Who are the high-risk patients who have risk of having babies with renal defects?

A. Renal defects are common if

• Previous sibling had defects like polycystic kidney disease which is an inherited kidney disease
 
• Other congenital defects associated affecting the spine, heart, gastrointestinal tract or chromosomal defects
 
• There is less liquor amnii i.e. oligohydramnios
 
• Death of previous sibling due to multiple defects
 
• Elderly mother
 
• If the marriage is in closely related individuals

Q. How does one screen for renal problems antenatally ?

A. Since antenatal sonography is a common and routine modality of investigation in pregnant women to assess maternal and fetal well being in many countries, it is used to detect congenital defects including renal problems. In our country, definite indications are

• Precious baby in an elderly woman
 
• Previous sibling with defect or death due to defects
 
• Oligohydramnios
 
• Assisted reproduction
 
• Parent's choice

Q. How can these renal defects be prevented?

A. Prevention of congenital defects in general can be

• Good care of mother as regards nutrition.
 
• Prevention of infection like Rubella, CMV, Toxoplasmosis etc by immunization against Rubella and screening in early pregnancy.
 
• Use of folic acid before conception to prevent neural tube defects.
 
• Regular antenatal visits and if antenatal sonography detects severe congenital defects including renal defects, medical termination of pregnancy is an option which requires counseling by a team of specialists in genetics, social worker, obstetrics, neonatologists, pediatric surgeon, psychologists etc.

Q. What are the chance of recurrence in future pregnancies ?

A. Chances of recurrence in future siblings are high in inherited diseases like Infantile polycystic kidney disease in which each sib has 25% chances of suffering from PKD.

Q. How can these renal problems be treated ?

A. Not all renal problems can be treated even if diagnosed antenatally. The ones with obstruction in the urinary tract, which can cause damage to the kidneys due to back-pressure need immediate attention i.e. hydronephrosis on both sides with posterior urethral valves or pelviureteric junction obstruction. Surgical treatment in unborn baby i.e. fetal surgery to relieve obstruction though possible is associated with complications in mother and high incidence of fetal loss. Hence, it is not advocated even in advanced countries. The best approach is to deliver the baby in a hospital with all the facilities for diagnosis and treatment of these renal problems. A team of doctors consisting of obstetrician, neonatologist, pediatric surgeon, radiologist, pediatric nephrologist and anesthetist can successfully manage these babies in the first few days after birth before the baby manifests problem like UT1, renal failure, failure to thrive, high BP etc.

Q. How do you follow up such a case ?

A. Many renal problems detected antenatally do not require surgery but regular follow up including growth monitoring, ultrasonography of kidneys to assess dilatation of urinary tract, urine examination and renal function test and nuclear scan of kidneys so that at the earliest sign of deterioration of kidney function or increase in dilatation; surgical intervention is planned. Many babies with mild to moderate hydronephrosis without obstruction resolve over 1½ - 2 years.

Last created on 18-09-2001
Last updated on 01-07-2006