This document summarizes antenatal diagnosis of kidney diseases. It discusses the incidence and types of congenital renal diseases detected prenatally. Diagnostic tools mentioned include fetal ultrasound, amniocentesis, and genetic testing. Key stages of kidney development are outlined. Features of various kidney anomalies detectable by ultrasound are described, such as bilateral renal agenesis, unilateral renal agenesis, cystic kidney diseases, antenatal hydronephrosis, and bladder anomalies. Associations with other structural abnormalities and recommendations for further evaluation are provided for different conditions.

1. ANTENATAL DIAGNOSIS OF
KIDNEY DISEASES
DR.SARITHA.S

2. CONGENITAL RENAL DISEASE
• Incidence- 1 to 4 in 1000 pregnancies.
• 15-20% of all prenatally diagnosed congenital anomalies.
• Obstructive uropathies accounts for the majority of cases.
• About 60% of children are undergoing surgery for renal or
urinary tract problems in their first five years of life are
identified by prenatal ultrasound

3. DIAGNOSIS
• FETAL ULTRASOUND.
• AMNIOCENTESIS.
• CHORIONIC VILLOUS SAMPLING.
• GENETIC TESTING.

4. KIDNEY DEVELOPMENT
• Pronephrons:3rd-4th week.
• Mesonephrons:5th-8th week-outgrowth of dorsomedial wall of
mesonephric tubules –ureteric duct.
• Metanephron: starts developing from 6th-10th week.
• Bladder develops –urogenital sinus.
• Urine production -9-11th week.

5. • Fetal kidneys – trans vaginal ultrasound- 10 to 12 weeks of
gestation.
• Fetal kidneys and adrenal glands- transabdominal ultrasound-
12th and 15th week of gestation.
• Corticomedullary differentiation -20th to 25th week of
gestation.
• Visualization of an echogenic reniform mass containing
hypoechoic medullary pyramids having the appearance of
sonolucent circles circumferentially arranged beneath the
renal cortical tissue.

6. • Colour flow doppler:
• The antero-posterior diameter of the renal pelvis (APPD)
should be:
– < 4 mm in the 2nd trimester.
– <7mm in the 3rd trimester.

7. • Fetal bladder - 13 weeks .
• A full fetal bladder is the best indicator of fetal urine
production.
• Nonvisualization of the fetal bladder combined with
oligohydramnios indicates severe pathology.
• Filling and emptying of the fetal bladder -30-45 mins.

8. • At 20 weeks about 90% of amniotic fluid consists of fetal
urine. Fetal urinary production:
– 7.3 ml/h at 24 weeks of pregnancy,
– 71.4 ml/h near term or about 300 ml/kg fetal weight/ day
(Gilbert et al., 1993; Lee et al., 2007; Touboul et al., 2008;
Peixoto et al., 2011

9. • Developmental renal defects include:
1. Bilateral/unilateral renal agenesis,
2. Renal hypoplasia / dysplasia with or without cysts,
3. and multicystic dysplastic kidney.
4. ADPKD/ARPKD/OTHER CYSTIC DISEASES.
5. Antenatal hydronephrosis.

10. • Ectopic kidneys - 1/1,000 pregnancies.
• Unilateral renal agenesis - 1/1,300 pregnancies.
• Bilateral renal agenesis -1/4,000 pregnancies.
•

11. BILATERAL RENAL AGENESIS
• The prenatal detection rate for bilateral renal agenesis- 84
and 91 %.
• Bilateral renal agenesis- absent kidneys, no colour doppler
flow, non visualisation of bladder,oligohydraminas.

12. • Fetal adrenals: The "laying down" sign refers to a flattened
appearance of adrenal glands on parasagittal imaging of the
abdomen, with a central hyperechoic layer sandwiched
between two hypoechoic areas.
• MRI: Signal void in a contracted bladder on T2-weighted MRI
indicates an empty bladder, which is one sign of a severe renal
anomaly such as renal agenesis.

13. • Renal agenesis is associated with an increased risk of other
structural abnormalities and chromosomal abnormalities
• Most cases of bilateral renal agenesis are sporadic.
• Recurrence of bilateral renal agenesis-3 to 6 %.
• 8 % in cases associated with multiple congenital
abnormalities.
• Approximately 9 to 14 percent of first degree relatives of
patients with bilateral renal agenesis or dysgenesis have renal
abnormalities.

14. Bilateral renal agenesis
• Association with other structural abnormalities in> 50% of
cases.
• VACTERL syndrome and isolated anomalies of the
cardiovascular , skeletal, and central nervous systems , Caudal
dysplasia syndrome , Sirenomelia, Potters syndrome.
• Early termination of pregnancy

15. UNILATERAL RENAL AGENESIS
• The prenatal detection rate for unilateral renal agenesis was
59 and 80 percent
• Unilateral renal agenesis is more difficult to diagnose .
• In unilateral renal agenesis, compensatory enlargement,
usually defined as renal length >95th percentile for
gestational age / anteroposterior to transverse diameter more
than 0.9 occurs in all cases and can be seen on ultrasound
starting at 20 weeks.

16. • Unilateral renal agenesis, urological anomalies occur in 48 to
65 percent of cases .
• The most common anomalies :
– vesicoureteral reflux (28 to 41 percent),
– ureterovesical junction obstruction (11 to 18 percent),
– and ureteropelvic junction obstruction (6 to 7 percent).
– 50% structural malformations of the heart , gastrointestinal
tract , genital, or skeletal systems.
– The incidence of a single umbilical artery is increased with
unilateral renal agenesis.
– With true unilateral agenesis, the ureter and the ipsilateral
bladder hemitrigone are absent.

17. • The absence of the vas deferens is the most frequent genital
anomaly in males with renal agenesis.
• One third of men with bilateral congenital absence of the vas
deferens have unilateral renal agenesis.
• Septate uterus is relatively common.
• Mayer-Rokitansky-Küster-Hauser syndrome

18. • Renal ectopic kidney has low incidence of chromosomal and
non chromosomal abnormalities.
• Horseshoe kidney: 5–8%: Turner syndrome and trisomy
18.

19. CYSTIC RENAL DISEASES
• Hereditary disorders
– Autosomal recessive polycystic kidney disease
– Autosomal dominant polycystic kidney disease
– Renal cysts seen
with syndromes/sequences (glomerulocystic and
medullary cystic dysplasia)
• Nonhereditary disorders
– Renal dysplasia
– Multicystic kidney disease
– Obstructive cystic dysplasia
• Nondysplastic nonhereditary renal cysts
– Renal cystic tumors
– Simple renal cysts

20. ARPKD ADPKD
1:20,000 live births(Recurrance -
25%)
1:400 to 1000 deliveries
PKHD 1 , HNF1B ,6p PKD1-16p, and PKD2- 4q.
Uniform, massive enlargement(4-
15 SD) of kidneys ,preservation of
the reniform shape ,Pyramidal
hyperechogenicity resembling
medullary nephrocalcinosis ,
isolated macroscopic cysts less
than 10 mm in size are visible in
the renal medulla in one third of
cases- Reversal of
corticomedullary differentiation
Moderately enlarged kidneys (1 to
2 SDs above the mean size for
gestational age)with a
hyperechogenic cortex. The
medulla can be hypoechogenic or
hyperechogenic- Increased CMD.
Dilatations of branching collecting
ducts .
Round cysts
Aminotic fliud-low Normal aminotic fluid.

22. • Presumptive diagnosis of ARPKD:
– neonatal mortality of 30 - 40 % due to pulmonary hypoplasia.
– One-year survival rates of 92 – 95% have been reported in patients
who survive the first month of life.

23. • Prenatal testing for is rarely considered for ADPKD that do not
affect intellect and have some effective therapies.
• A possible exception may be in rare families where severe,
early-onset disease in one child suggests a significant risk of
recurrence of severe disease in a sibling.
• Preimplantation genetic testing has been performed in some
cases; it is available in some countries and should be included
in the discussion of reproductive choices with patients with
ADPKD

24. ANTENATAL HYDRONEPHROSIS
• the prevalence of antenatally detected hydronephrosis (ANH)
ranges from 0.6-5.4%
• Bilateral : 17-54%.

25. • Antenatal hydronephrosis is present if the APD is ≥4 mm in
second trimester and ≥7 mm in the third trimester.

26. • If antenatal hydronephrosis is detected, ultrasound at 16-20
weeks gestation and evaluation for lower urinary tract
obstruction, renal dysplasia and extrarenal structural
malformations .
• Fetuses with antenatal hydronephrosis, and a major structural
anomaly or additional soft sign(s) be referred to an obstetric
unit with facilities for genetic counseling and prenatal testing

28. Bladder anamolies
• Bladder is enlarged or it is not visible.
• Megacystis -A bladder with longitudinal diameter > 7 mm in
the first trimester.
• Megacystis - is associated with a 25% risk of chromosomal
defects, karyotyping is recommended .

29. Thank you