Fetal Hyperechogenic Kidneys Research Articles

Prenatal diagnosis in the fetal hyperechogenic kidneys: assessment using chromosomal microarray analysis and exome sequencing

Fetal hyperechogenic kidneys (HEK) is etiologically a heterogeneous disorder. The aim of this study was to identify the genetic causes of HEK using prenatal chromosomal microarray analysis (CMA) and exome sequencing (ES). From June 2014 to September 2022, we identified 92 HEK fetuses detected by ultrasound. We reviewed and documented other ultrasound anomalies, microscopic and submicroscopic chromosomal abnormalities, and single gene disorders. We also analyzed the diagnostic yield of CMA and ES and the clinical impact the diagnosis had on pregnancy management. In our cohort, CMA detected 27 pathogenic copy number variations (CNVs) in 25 (25/92, 27.2%) fetuses, with the most common CNV being 17q12 microdeletion syndrome. Among the 26 fetuses who underwent further ES testing, we identified 7 pathogenic/likely pathogenic variants and 8 variants of uncertain significance in 9 genes in 12 fetuses. Four novel variants were first reported herein, expanding the mutational spectra for HEK-related genes. Following counseling, 52 families chose to continue the pregnancy, and in 23 of them, postnatal ultrasound showed no detectable renal abnormalities. Of these 23 cases, 15 had isolated HEK on prenatal ultrasound. Taken together, our study showed a high rate of detectable genetic etiologies in cases with fetal HEK at the levels of chromosomal (aneuploidy), sub-chromosomal (microdeletions/microduplications), and single gene (point mutations). Therefore, we speculate that combined CMA and ES testing for fetal HEK is feasible and has good clinical utility. When no genetic abnormalities are identified, the findings can be transient, especially in the isolated HEK group.

Fetal hyperechogenic kidneys: the significance of family assessment.

A 35 yr GVPI; with 2 early pregnancy losses and 1 late abortion was referred because anhydramnios and bilateral cystic kidney dysplasia had been diagnosed in the previous pregnancy. This was confirmed by autopsy after late abortion in the 19th week of gestation and genetic testing had been denied. A subsequent pregnancy was unremarkable with no evidence of fetal kidney disease and resulted in a now 10month old daughter.

Prenatal diagnosis and outcome of fetal hyperechogenic kidneys in the era of antenatal next-generation sequencing

BackgroundFetalhyperechogenickidneys (HEK)are associated with a wide range of etiologies and prognoses. Prenatal counselling and management can be extremely challenging, especially for isolated HEK. MethodsA total of 28 pregnancies were screened by ultrasonography with HEK from March 1, 2016 to December 31, 2020. Genetic testings for aneuploidy and copy number variations (CNVs) are routine during the investigation for etiologies of fetal HEK in our unit. Trio-whole exome sequencing(WES) was offered to the family when karyotyping and microarray were not diagnostic.A systematic review (SR) was conducted to use the authoritative literature retrieval databases describing genetic testings’ results in prenatal HEK cases. ResultsIn the 28 HEK fetuses, 2 (7.14%) cases were identified with chromosome abnormalities and 6 (21.43%) cases were detected with pathogenic CNVs. Through trio-WES analysis, pathogenic or likely pathogenic variations were detected in the following genes: PKD1, BBS2, BBS9, HNF1B, PKHD1 and ETFA in another 10 (35.71%) fetuses. And the remaining 10 (35.71%) cases were undiagnosed. The pooled data from all reviewed studies indicate that HNF1B gene heterozygous deletion or mutation are the most common genetic causes associated with HEK. ConclusionThis is the first study to accurately describe the genotype ratio at different levels of genetic testing associated with fetal HEK. Our study has suggested that trio-WES could improve the detection rate and efficiency ofidentification genetic pathologies in fetuseswith isolated HEK. The WES results provide new evidences to guide prenatal counseling and management.

Etiologies and outcomes of prenatally diagnosed hyperechogenic kidneys.

To determine etiologies and outcomes of fetal hyperechogenic kidneys (HEK). We conducted a retrospective chart review of HEK in British Columbia (January 2013-December 2019) and literature review. We identified 20 cases of HEK without other anomalies (isolated) in our provincial cohort, one was lost to follow-up. Eight had testable genetic etiologies (autosomal dominant polycystic kidney disease [ADPKD], autosomal recessive polycystic kidney disease [ARPKD], Bardet-Biedl syndrome [BBS], and HNF1B-related disorder). The remaining seven did not have an identifiable genetic etiology. Of cases without a genetic etiology with postnatal follow-up (n=6) there were no abnormalities of blood pressure, creatinine/estimated glomerular filtration rate or urinalysis identified with follow-up from 2-71months. We report 11 cases with extrarenal anomalies (nonisolated), with outcomes and etiologies. We identified 224 reported cases of isolated HEK in the literature. A potentially testable genetic etiology was found in 128/224 (57.1%). The neonatal death rate in those with testable etiologies was 17/128 (13.3%) compared to 2/96 (2.1%) when testable etiologies were excluded. Genetic etiologies (ARPKD, ADPKD, BBS, HNF1B-related disorder, Beckwith-Wiedemann syndrome, tubular dysgenesis, familial nephroblastoma, and cytogenetic abnormalities) account for approximately half of prenatally isolated HEK; once excluded there are few neonatal deaths and short-term renal outcomes may be normal. There remains a paucity of knowledge about long-term renal outcomes.

Hyperechogenic Fetal Kidneys: Uncertain Diagnosis and Unpredictable Future?

AbstractGlomerulocystic kidney with increased renal echogenicity encompasses a number of renal abnormalities that might have cystic glomeruli and be a sequelae of renal obstruction. Increased echogenicity of the kidneys is a non-specific finding and a result of varied etiologies. Multiple microscopic cortical and medullary cysts, interstitial fibrosis and mesangial sclerosis are the etiopathogenesis for renal hyperechogenicity even in the absence of macrocysts. The crucial point is poor predictability of antenatal ultrasound to fully define the extent and severity of parenchymal damage and to forecast its outcome at the time of initial diagnosis. The only exception is the most severe forms of cystic dysplasia associated with severe oligohydramnios. Urinary levels of β2-microglobulin may be a valuable marker of fetal renal function. Hyperechogenic fetal kidneys may have varied etiologies and within each etiological group there may have a wide range of outcomes. Challenges lie in counseling after antenatal diagnosis of fetal hyperechogenic kidneys which carry an uncertain course and prognosis.

P05.03: Antenatal sonographic and genetic diagnosis of two cases of Bardet‐Biedl syndrome

Bardet-Biedl syndrome (BBS) belongs to the group of ciliopathies and has an autosomal-recessive inheritance with 22 genes known already. In the child it is associated with retinal dystrophy, obesity, neurological and psychic disabilities, hypogonadism, postaxial polydactyly and renal dysfunction. There are overlapping with other ciliopathies. Prenatal report of BBS is rather scarce. We report the features of two prenatally confirmed cases of BBS. Case 1: On screening US at 22 weeks (G2-P1) in a non-consanguineous patient enlarged, fetal hyperechogenic kidneys were detected. The detailed examination showed a hexadactyly at one foot, with no other malformations. A BBS was suspected and amniocentesis revealed a homozygotic mutation in the BBS1 gene. Both parents were found to be heterozygote carriers. The parents opted for pregnancy termination. Case 2: In the primigravida non-consanguineous 30y old patient first trimester screening revealed a polydactyly of both hands and feet with no additional anomalies. CVS showed a male karyotype. A follow up at 18 weeks showed in addition large hyperechogenic kidneys with no other signs of a ciliopathy. Bardet-Biedl syndrome was suspected and a deletion of exons 14-17 of the BBS-1 was found. Both parents were found to be heterozygote carriers. Patient opted for pregnancy termination. Prenatal diagnosis of BBS remains difficult but these two cases show that the presence of hyperechogenic kidneys and polydactyly only should prompt the careful targeted examination for a BBS. The additional presence of intracerebral, skeletal or other malformations can be the hint for other ciliopathies, including Joubert or Meckel syndrome. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Prenatal hyperechogenic kidneys in three cases of infantile hypercalcemia associated with SLC34A1 mutations

Prenatal diagnosis of hyperechogenic kidneys is associated with a wide range of etiologies and prognoses. The recent advances in fetal ultrasound associated with the development of next-generation sequencing for molecular analysis have enlarged the spectrum of etiologies, making antenatal diagnosis a very challenging discipline. Of the various known causes of hyperechogenic fetal kidneys, calcium and phosphate metabolism disorders represent a rare cause. An accurate diagnosis is crucial for providing appropriate genetic counseling and medical follow-up after birth. We report on three cases of fetal hyperechogenic kidneys corresponding to postnatal diagnosis of nephrocalcinosis. In all cases, antenatal ultrasound showed hyperechogenic kidneys of normal to large size from 22 gestational weeks, with a normal amount of amniotic fluid. Postnatal ultrasound follow-up showed nephrocalcinosis associated with hypercalcemia, hypercalciuria, elevated 1,25(OH)2-vitamin D, and suppressed parathyroid hormone levels. Molecular genetic analysis by next-generation sequencing performed after birth in the three newborns revealed biallelic pathogenic variants in the SLC34A1 gene, encoding the sodium/phosphate cotransporter type 2 (Npt2a), confirming the diagnosis of infantile hypercalcemia. Nephrocalcinosis due to infantile hypercalcemia can be a cause of fetal hyperechogenic kidneys, which suggests early antenatal anomaly of calcium and phosphate metabolism. This entity should be considered in differential diagnosis. Postnatal follow-up of infants with hyperechogenic kidneys should include evaluation of calcium and phosphate metabolism.

Clinical phenotypes of hepatocyte nuclear factor 1 homeobox b-associated disease

Objective: Hepatocyte nuclear factor 1 homeobox b (HNF1B) -associated disease is an autosomal dominant inherited disorder with a variable, multi-systemic phenotype. In China, five adult probands and one child proband with HNF1B-associated disease had been reported, whereas few fetuses are described. The aims of this retrospective study were to understand about the clinical manifestations of HNF1B-associated disease and to further improve the recognition of this disorder. Method: Four patients (3 males, 1 female) and three fetuses with HNF1B mutations were included in this study. They were admitted to our hospital from January 2013 to March 2017. HNF1B mutations were detected using targeted next generation sequencing and quantitative real-time PCR or Sanger sequencing. HNF1B heterozygous deletion of exons 1-9 was found in 4 patients and 2 fetuses, and HNF1B heterozygous missense mutation in 1 fetus. These two mutations had been reported. Two patients and 1 fetus had de novo mutations. Results of renal ultrasonography with or without magnetic resonance imaging, biochemical investigations, urine routine examination and other necessary investigations in 7 cases were analyzed. Result: Three patients were Han Chinese ethnicity, and one patient was Mongolian. In patients 1 and 4, abnormal fetal kidneys were discovered by routine ultrasonography, and the age at first feature identified in Patients 2 and 3 were 13 years and 28 years. Patient 3 had normal renal function and the remainder had reduced glomerular filtration rate. In addition, patient 4 presented with nephrotic syndrome and glycosuria, patient 2 with early onset hyperparathyroidism and renal osteodystrophy, and patient 3 with diabetes mellitus. All the 4 patients had renal structural abnormalities including bilateral multiple renal cysts, dysplasia and hyperechogenic kidneys. Only patient 3 had a positive family history of renal diseases, the remainder had a negative family history of renal diseases. In 3 fetuses, prenatal ultrasound anomalies were detected during the second trimester. These 3 fetuses had hyperechogenic kidneys with or without renal cysts. Polyhydramnios was detected in only one of the 3 fetuses. Two of the 3 fetuses had a positive family history of renal diseases. Conclusion: Clinical phenotypes of HNF1B-related disease are heterogeneous, renal malformations clearly appear to be the most common manifestation, multiple renal cysts are characteristic, and patients can progress to impaired kidney function during childhood; HNF1B mutation is a differential diagnosis of fetal hyperechogenic kidneys or multiple renal cysts.

Prenatal diagnosis of 17q12 deletion syndrome: from fetal hyperechogenic kidneys to high risk for autism.

The linkage between 17q12 microdeletions, renal anomalies, and higher risk for neurodevelopmental disorders is well described in the literature. The current study presents prenatal diagnosis of normal-sized fetal hyperechogenic kidneys leading to the diagnosis of 17q12 deletion syndrome and autism spectrum disorder. Over a period of 9 years in a single referral center, seven fetuses were diagnosed with hyperechogenic renal parenchyma and were followed up prospectively. Amniocentesis for molecular diagnosis was performed in all cases, and subsequently, five fetuses were found to harbor a 17q12 deletion by chromosomal microarray analysis. Postnatal evaluation was carried out by a developmental neurologist. Five of the seven fetuses had molecular diagnosis of 17q12 deletion. One patient elected termination of pregnancy. On long-term follow-up, all of the four children showed symptoms consistent with neurodevelopmental disorders. The two fetuses with no deletion have a normal follow-up with regression of the renal hyperechogenicity. We report a strikingly high correlation between prenatal hyperechogenic kidneys, 17q12 microdeletion, and autism spectrum disorder with the advantage of optimal prenatal counseling as well as early diagnosis and intervention. © 2016 John Wiley & Sons, Ltd.

P25.04: Prenatal diagnosis of 17q12 deletion syndrome: from fetal hyperechogenic kidneys to high risk for autism

P25.04: Prenatal diagnosis of 17q12 deletion syndrome: from fetal hyperechogenic kidneys to high risk for autism

OP32.06: Isolated bilateral fetal hyperechogenic kidneys: outcome and prognostic factors

OP32.06: Isolated bilateral fetal hyperechogenic kidneys: outcome and prognostic factors

Simplified screening criteria for HNF1B analysis

To the Editor: Indications for HNF1B analysis in subjects with congenital anomalies of kidneys and urinary tract (CAKUT) remain controversial and a frequently discussed subject. The large phenotypic variability and the high rate of de novo mutations partly explain this discussion. Recently, Faguer et al.1Faguer S. Chassaing N. Bandin F. et al.The HNF1B score is a simple tool to select patients for HNF1B gene analysis.Kidney Int. 2014; 86: 1007-1015Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar have addressed this challenging issue by developing an exhaustive scoring system. This 17-item score contains clinical, biochemical, familial, and pathological findings in affected subjects. Although the authors claim that their score performed with a sensitivity of 98.2% and a NPV of 99%, we have some connotations to address. We recently applied the score of Faguer et al.1Faguer S. Chassaing N. Bandin F. et al.The HNF1B score is a simple tool to select patients for HNF1B gene analysis.Kidney Int. 2014; 86: 1007-1015Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar in a cohort of children and adults identified with HNF1B mutations in a prospective cohort of patients with CAKUT2Raaijmakers A. Corveleyn A. Devriendt K. et al.Criteria for HNF1B analysis in patients with congenital abnormalities of kidney and urinary tract.Nephrol Dial Transplant. 2014; (e-pub ahead of print 13 December 2014)PubMed Google Scholar and found that three patients would have been missed, as especially in children an exhaustive list of symptoms is not always (yet) present. In contrast, applying the simplified screening criteria excluding patients with unilateral abnormalities in the absence of major criteria (fetal hyperechogenic kidneys, multicystic dysplastic kidney, renal agenesis, hypoplastic or dysplastic kidneys, or cysts from unknown origin)2Raaijmakers A. Corveleyn A. Devriendt K. et al.Criteria for HNF1B analysis in patients with congenital abnormalities of kidney and urinary tract.Nephrol Dial Transplant. 2014; (e-pub ahead of print 13 December 2014)PubMed Google Scholar would improve the detection rate from 10 to 19% and a 50% reduction in patients to be screened, in line with the improvement by the score of Faguer et al.1Faguer S. Chassaing N. Bandin F. et al.The HNF1B score is a simple tool to select patients for HNF1B gene analysis.Kidney Int. 2014; 86: 1007-1015Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar In our opinion, an easy screening protocol proposed in our study is suitable for daily clinical practice, although we realize that both protocols should be applied to larger databases to substantiate their use and to validate their performance. This study was supported by the “Agency for Innovation, Science and Technology in Flanders (IWT) through the “SAFEPEDRUG” project (IWT/SBO 120033)”

O-182 Hnf1b Mutations In Patients With Congenital Abnormalities Of Kidney And Urinary Tract (cakut): Are We Screening Too Much?

Background and aims Hepatocyte nuclear factor 1 beta (HNF1B) is involved in the development of kidneys, liver, pancreas and urogenital tract. Disorders have an extremely high heterogeneity in phenotype. We aim to define accurate criteria for screening in a prospective cohort of patients. Methods Based on the phenotypic characteristics described in literature, we defined major, minor and extra-renal selection criteria. Major criteria were defined as fetal bilateral hyperechogenic kidneys; multicystic dysplastic kidney or renal agenesis; hypoplastic or dysplastic kidneys or cysts from unknown origin. Minor criteria were defined as ectopic kidney; vesico-ureteral reflux; hydronephrosis and extrarenal criteria as diabetes; hypomagnesemia; hyperuricemia; hypokalemia; liver function abnormalities or positive familial history. We included all patients from our paediatric and adult nephrology department from January 2010 till April 2013 presenting with at least one major or one minor criterion with extra-renal manifestations in the personal or familial history. Results We screened a prospective cohort of 252 patients fitting the criteria mentioned above and detected HNF1B mutations in 10% (n = 20), with a complete deletion being the most common (n = 10), besides duplication or sequence abnormalities. In our cohort the best predictors for finding HNF1B mutations were bilateral renal abnormalities (p Conclusions Based on a prospective single centre cohort, we demonstrated that HNF1B-mutations are responsible for approximately 10% of CAKUT cases. Nonetheless, bilateral renal anomalies or cysts from unknown origin were the best predictors. These criteria might be useful for a more restricted screening protocol, but should be reaffirmed in a larger multicenter cohort.

Anomalies of the TCF2 Gene Are the Main Cause of Fetal Bilateral Hyperechogenic Kidneys

Prenatal discovery of fetal bilateral hyperechogenic kidneys is very stressful for pregnant women and their family, and accurate diagnosis of the cause of the moderate forms of this pathology is very difficult. Hepatocyte nuclear factor-1beta that is encoded by the TCF2 gene is involved in the embryonic development of the kidneys. Sixty-two pregnancies with fetal bilateral hyperechogenic kidneys including 25 fetuses with inaccurate diagnosis were studied. TCF2 gene anomalies were detected in 18 (29%) of these 62 patients, and 15 of these 18 patients presented a complete heterozygous deletion of the TCF2 gene. Family screening revealed de novo TCF2 anomalies in more than half of the patients. TCF2 anomalies were associated with normal amniotic fluid volume and normal-sized kidneys between -2 and +2 SD in all patients except for two sisters. Antenatal cysts were detected in 11 of 18 patients, unilaterally in eight of 11. After birth, cysts appeared during the first year (17 of 18), and in patients with antenatal cysts, the number increased and developed bilaterally with decreased renal growth. In these 18 patients, the GFR decreased with longer follow-up and was lower in patients with solitary functioning dysplastic kidney. Heterozygous deletion of the TCF2 gene is an important cause of fetal hyperechogenic kidneys in this study and showed to be linked with early disease expression. The renal phenotype and the postnatal evolution were extremely variable and need a prospective long-term follow-up. Extrarenal manifestations are frequent in TCF2-linked pathologies. Therefore, prenatal counseling and follow-up should be multidisciplinary.

Differential diagnosis of fetal hyperechogenic cystic kidneys unrelated to renal tract anomalies: a multicenter study

To identify important factors in the differential diagnosis of renal cysts associated with hyperechogenic kidneys. This was a retrospective multicenter study. We identified 93 fetuses presenting between 1990 and 2002 with hyperechogenic kidneys and which had a diagnosis of nephropathy confirmed later. We analyzed retrospectively the prenatal ultrasound findings of those fetuses which were found sonographically to have renal cysts. Of the 93 fetuses presenting with hyperechogenic kidneys and with a later diagnosis of nephropathy, there were 28 with autosomal dominant polycystic kidney disease (ADPKD), 31 with autosomal recessive polycystic kidney disease (ARPKD), 11 with Bardet-Biedl syndrome, nine with Meckel-Gruber syndrome, six with Ivemark II syndrome, one with Jarcho-Levin syndrome, one with Beemer syndrome and one with Meckel-like syndrome. One third of the fetuses (30/93) had renal cysts. Cystic characteristics (size, location, number) were not very useful for diagnosis; more useful was diagnosis of an associated malformation. Three (11%) of the fetuses with ADPKD had cysts, as did nine (29%) of those with ARPKD, three (27%) of those with Bardet-Biedl syndrome, all (100%) of those with Meckel-Gruber syndrome, three (50%) of those with Ivemark II syndrome, and each of the three cases with other syndromes (Jarcho-Levin, Beemer and Meckel-like syndromes). None of the cases with trisomy 13 had cysts. There were no associated malformations in the 12 cases with renal cysts and polycystic kidney disease; the other 18 cases with renal cysts were associated with malformations that were often specific, such as polydactyly in Bardet-Biedl and Beemer syndromes, occipital defect and Dandy-Walker malformation in Meckel-Gruber or Meckel-Gruber-like syndromes, and thoracic and/or vertebral abnormalities in Jarcho-Levin and Beemer syndromes. Renal cysts associated with hyperechogenic kidneys are not rare. The clue to diagnosis is the demonstration of an associated malformation. If no malformation is found, the main diagnosis remains polycystic kidney disease, i.e. ARPKD or ADPKD.

Bilateral fetal hyperechogenic kidneys associated with normal amniotic fluid: an ethical dilemma in a normal variant?

Bilateral fetal hyperechogenic kidneys associated with normal amniotic fluid: an ethical dilemma in a normal variant?

Fetal hyperechogenic kidney with normal amniotic fluid volume: a diagnostic dilemma

To determine the prognostic value of sonographically detected fetal hyperechogenic kidneys with normal amniotic fluid volume. Seven cases of hyperechogenic fetal kidneys were identified by sonography over a 7-year period (1996--2002). Increased renal echogenicity was diagnosed when the renal parenchyma was of greater echogenicity than adjacent liver tissue. Amniotic fluid volume was measured by the semiquantitative sonographic technique known as the amniotic fluid index (AFI). Three of the live-born infants had autosomal dominant polycystic kidney disease and one had autosomal recessive polycystic kidney. In the remainder, autopsy study revealed multifocal renal dysplasia in two cases and normal kidneys in one. Increased renal echogenicity with normal amniotic fluid volume in a fetus without other anomalies is a difficult diagnostic dilemma. Although it is usually indicative of renal parenchymal disease with possible renal failure after birth or in early childhood, in some cases, it represents a normal variant. .

OC062: Fetal hyperechogenic kidneys: causes and long term outcome in 43 cases

OC062: Fetal hyperechogenic kidneys: causes and long term outcome in 43 cases

Prenatal diagnosis of bilateral isolated fetal hyperechogenic kidneys. Is it possible to predict long term outcome?

To study perinatal and long term outcome following prenatal diagnosis of hyperechogenic kidneys. Prospective observational cohort study. The Maternité Port-Royal Hôpital Cochin and at the Departments of Obstetrics and Paediatric Nephrology, Necker Enfants Malades in Paris, France. Forty-three fetuses with isolated bilateral hyperechogenic kidneys. All patients referred with isolated bilateral hyperechogenic fetal kidneys were followed up prospectively up to 34-132 months. The following prenatal items were analysed: fetal kidney size, amniotic fluid volume, gestational age at diagnosis, family history and renal ultrasound in parents. Postmortem examination was carried out in cases with perinatal death. Postnatal follow up of survivors included postnatal ultrasound, blood pressure, serum creatinine, proteinuria, need for restricted diet, weight and height and renal biopsy when available. Aetiology of hyperechogenicity, perinatal mortality and renal function in survivors. The aetiology could be established by family history, postmortem or postnatal data, but not by prenatal ultrasound. There were 20 autosomal recessive, 8 autosomal dominant polycystic kidney diseases, 9 other renal disorders and 6 symptom-free survivors without aetiological diagnosis. There were 19 terminations of pregnancy, 5 neonatal deaths and 19 survivors, of whom 14 had normal renal function three had mild and two had end stage renal failure. None of those with severe oligohydramnios and fetal kidneys > 4 SD survived (n = 14, 10 terminations and 4 neonatal deaths), whereas of the 17 with normal amniotic fluid volume and kidneys < 4 SD, 14 survived, of whom 9 were symptom-free. Aetiology could not be established prenatally in the absence of familial data. Kidney size and amniotic fluid volume were the best prenatal predictors of outcome.

Prenatal diagnosis of bilateral isolated fetal hyperechogenic kidneys. Is it possible to predict long term outcome?

Objective To study perinatal and long term outcome following prenatal diagnosis of hyperechogenic kidneys. Design Prospective observational cohort study. Setting The Maternité Port-Royal Hôpital Cochin and at the Departments of Obstetrics and Paediatric Nephrology, Necker Enfants Malades in Paris, France. Population Forty-three fetuses with isolated bilateral hyperechogenic kidneys. Methods All patients referred with isolated bilateral hyperechogenic fetal kidneys were followed up prospectively up to 34–132 months. The following prenatal items were analysed: fetal kidney size, amniotic fluid volume, gestational age at diagnosis, family history and renal ultrasound in parents. Postmortem examination was carried out in cases with perinatal death. Postnatal follow up of survivors included postnatal ultrasound, blood pressure, serum creatinine, proteinuria, need for restricted diet, weight and height and renal biopsy when available. Main outcome measures Aetiology of hyperechogenicity, perinatal mortality and renal function in survivors. Results The aetiology could be established by family history, postmortem or postnatal data, but not by prenatal ultrasound. There were 20 autosomal recessive, 8 autosomal dominant polycystic kidney diseases, 9 other renal disorders and 6 symptom-free survivors without aetiological diagnosis. There were 19 terminations of pregnancy, 5 neonatal deaths and 19 survivors, of whom 14 had normal renal function three had mild and two had end stage renal failure. None of those with severe oligohydramnios and fetal kidneys > 4 SD survived ( n = 14, 10 terminations and 4 neonatal deaths), whereas of the 17 with normal amniotic fluid volume and kidneys < 4 SD, 14 survived, of whom 9 were symptom-free. Conclusion Aetiology could not be established prenatally in the absence of familial data. Kidney size and amniotic fluid volume were the best prenatal predictors of outcome.