Antenatal presentation and early postnatal treatment of infantile hypercalcemia type 2.

Infantile hypercalcemia (IH) is a rare genetic disorder characterized by hypercalcemia, hypercalciuria, low parathyroid hormone, and nephrocalcinosis during the first months of life. Biallelic variants in the genes CYP24A1 and SCL34A1 cause IH1 and 2, respectively. We present the case of a newborn with an antenatal diagnosis of IH2 due to the identification of echogenic, yet normal-sized kidneys at 23 weeks gestation. Trio whole-exome sequencing initially identified only a heterozygous pathogenic variant in SLC34A1. Re-analysis of the exome data because of the clinical suspicion of IH2 revealed a 21-basepair deletion in trans that had initially been filtered out because of its high allele frequency. The diagnosis of IH2 enabled postnatal screening for hypercalcemia, present already at week 1, resulting in early treatment with phosphate supplementation and vitamin D avoidance. In the subsequent course, biochemical parameters were normalized, and the patient showed no obvious clinical complications of IH2, apart from the nephrocalcinosis.

Amniotic fluid peptides predict postnatal kidney survival in developmental kidney disease.

Although a rare disease, bilateral congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of end stage kidney disease in children. Ultrasound-based prenatal prediction of postnatal kidney survival in CAKUT pregnancies is far from accurate. To improve prediction, we conducted a prospective multicenter peptidome analysis of amniotic fluid spanning 140 evaluable fetuses with CAKUT. We identified a signature of 98 endogenous amniotic fluid peptides, mainly composed of fragments from extracellular matrix proteins and from the actin binding protein thymosin-ß4. The peptide signature predicted postnatal kidney outcome with an area under the curve of 0.96 in the holdout validation set of patients with CAKUT with definite endpoint data. Additionally, this peptide signature was validated in a geographically independent sub-cohort of 12 patients (area under the curve 1.00) and displayed high specificity in non-CAKUT pregnancies (82 and 94% in 22 healthy fetuses and in 47 fetuses with congenital cytomegalovirus infection respectively). Change in amniotic fluid thymosin-ß4 abundance was confirmed with ELISA. Knockout of thymosin-ß4 in zebrafish altered proximal and distal tubule pronephros growth suggesting a possible role of thymosin ß4 in fetal kidney development. Thus, recognition of the 98-peptide signature in amniotic fluid during diagnostic workup of prenatally detected fetuses with CAKUT can provide a long-sought evidence base for accurate management of the CAKUT disorder that is currently unavailable.

Analysis of renal blood flow and renal volume in normal fetuses and in fetuses with a solitary functioning kidney.

OBJECTIVE: To evaluate renal blood flow and renal volume for the prediction of postnatal renal function in fetuses with solitary functioning kidney (SFK). METHODS: Seventy-four SFK fetuses (unilateral renal agenesis [12], multicystic dysplastic kidney [36], and severe renal dysplasia [26]) were compared with 58 healthy fetuses. Peak systolic velocity (PSV), pulsatility index (PI), and resistance index (RI) of the renal artery (RA) were measured; 2D and 3D (VOCAL) volumes were calculated. Renal length and glomerular filtration rate (GFR) were obtained in SFK children (2 years). RESULTS: Compared with the control group, the PSV RA was significantly lower in nonfunctioning kidneys and significantly higher in SFK. Volume measurements indicated a significantly larger volume of SFK compared with healthy kidneys. All but 4 children had GFR above 70 mL/min/1.73 m2 , and compensatory hypertrophy was present in 69% at 2 years. PSV RA and SFK volume correlated with postnatal renal hypertrophy. No correlation between prenatal and postnatal SFK volume and GFR at 2 years was demonstrated. CONCLUSION: Low PSV RA might have a predictive value for diagnosing a nonfunctioning kidney in fetuses with a SFK. We demonstrated a higher PSV RA and larger renal volume in the SFK compared with healthy kidneys.

Termination of pregnancy for renal malformations.

BACKGROUND: We studied the correlation between prenatal diagnosis and postmortem investigations in pregnancies terminated for renal malformations. METHODS: Over a 5-year period, 77 cases of termination of pregnancy (TOP) for renal malformations were reviewed. Chromosomal anomalies (n = 9) and cases without conventional or virtual autopsy were excluded (n = 15). In 53 cases, prenatal ultrasound diagnosis and conventional autopsy findings were compared. In addition, we compared the accuracy of conventional and virtual autopsy findings in 17 cases. RESULTS: Full agreement was observed in 60.4% (32/53) of cases. In 26.4% (14/53) of the cases, the presence of additional malformations did not alter the final diagnosis. However, in 11.3% (6/53) the final diagnosis was adjusted because of major additional findings. One case showed a total disagreement. Conventional and virtual autopsy were in full agreement in 52.9% (9/17). Postmortem magnetic resonance imaging (MRI) description and detection of malformations was less complete and failed to correctly diagnose 5/17 cases (29.4%). In 17.6% (3/17) of the cases, postmortem MRI revealed malformations not confirmed by conventional autopsy. CONCLUSIONS: A high correlation between prenatal ultrasound and postmortem investigations was observed. Conventional autopsy remains the gold standard to reveal additional major and minor malformations, leading to a correct final diagnosis. The added value of virtual necropsy for renal pathology was limited.

Early fetal anatomy screening: who, what, when and why?

PURPOSE OF REVIEW: This article reviews the potential benefits and downsides of early anatomy screening. RECENT FINDINGS: There is increasing evidence that about 50% of severe fetal anomalies can be diagnosed prior to 14 weeks of gestation. 'Red flags' such as an increased nuchal or intracranial translucency, tricuspid valve regurgitation, a small biparietal diameter, a single umbilical artery or an abnormal retronasal triangle should raise the sonographer's suspicion of a congenital defect and warrant a more thorough fetal assessment, which often includes transvaginal scanning. Care should, however, be taken not to overinterpret first-trimester findings as false-positive rates of 3-4% have been reported. With more subtle findings, and especially if a heart defect is suspected, a sonographic reassessment after 15 weeks' gestation is indicated. Patients should be counseled that findings could worsen but also improve with time. SUMMARY: Basic fetal anomaly screening should be recommended, piggybacked on the routine first-trimester (aneuploidy screening) ultrasound, both for low and high-risk populations. First-trimester anatomy screening seems particularly useful in obese women, whose fetuses are difficult to screen at the midtrimester ultrasound and in multiple gestation. Noninvasive prenatal testing using cell-free fetal DNA can complement but should not replace first-trimester ultrasound.

Postmortem high-resolution fetal magnetic resonance imaging in three cases of lower urinary tract obstruction.

In this manuscript we report 3 cases of severe lower urinary tract obstruction diagnosed before 20 weeks of pregnancy. All cases had a very similar prenatal presentation with a megacystis, bilateral hydro-ureteronephrosis and increased echogenicity of the kidneys. High-resolution postmortem magnetic resonance imaging (MRI), following termination of pregnancy, enabled accurate investigation of the underlying cause of the urinary tract obstruction, by depicting the presence of an urethral valve, urethral atresia and cloacal dysgenesis. Postmortem fetal MRI provides high anatomical detail and is very suitable to investigate congenital anomalies of the lower urinary tract. In case (timely or consented) conventional autopsy is not possible, MRI is an excellent alternative.

Novel perspectives for investigating congenital anomalies of the kidney and urinary tract (CAKUT).

Congenital anomalies of the kidney and urinary tract (CAKUT) are the commonest cause of chronic kidney disease in children. Structural anomalies within the CAKUT spectrum include renal agenesis, kidney hypo-/dysplasia, multicystic kidney dysplasia, duplex collecting system, posterior urethral valves and ureter abnormalities. While most CAKUT cases are sporadic, familial clustering of CAKUT is common, emphasizing a strong genetic contribution to CAKUT origin. Animal experiments demonstrate that alterations in genes crucial for kidney development can cause experimental CAKUT, while expression studies implicate mislocalization and/or aberrant levels of the encoded proteins in human CAKUT. Further insight into the pathogenesis of CAKUT will improve strategies for early diagnosis, follow-up and treatment. Here, we outline a collaborative approach to identify and characterize novel factors underlying human CAKUT. This European consortium will share the largest collection of CAKUT patients available worldwide and undertake multidisciplinary research into molecular and genetic pathogenesis, with extension into translational studies to improve long-term patient outcomes.

Postmortem fetal imaging of a metabolic pluricystic kidney disease.

Postmortem magnetic resonance images of a pluricystic kidney disease due to an inborn error of the fatty acid metabolism are presented.

Enhanced MCP-1 Release in Early Autosomal Dominant Polycystic Kidney Disease.

INTRODUCTION: Autosomal dominant polycystic kidney disease (ADPKD) causes kidney failure typically in adulthood, but the disease starts in utero. Copeptin, epidermal growth factor (EGF), and monocyte chemoattractant protein-1 (MCP-1) are associated with severity and hold prognostic value in adults but remain unstudied in the early disease stage. Kidneys from adults with ADPKD exhibit macrophage infiltration, and a prominent role of MCP-1 secretion by tubular epithelial cells is suggested from rodent models. METHODS: In a cross-sectional study, plasma copeptin, urinary EGF, and urinary MCP-1 were evaluated in a pediatric ADPKD cohort and compared with age-, sex-, and body mass index (BMI)-matched healthy controls. MCP-1 was studied in mouse collecting duct cells, human proximal tubular cells, and fetal kidney tissue. RESULTS: Fifty-three genotyped ADPKD patients and 53 controls were included. The mean (SD) age was 10.4 (5.9) versus 10.5 (6.1) years (P = 0.543), and the estimated glomerular filtration rate (eGFR) was 122.7 (39.8) versus 114.5 (23.1) ml/min per 1.73 m2 (P = 0.177) in patients versus controls, respectively. Plasma copeptin and EGF secretion were comparable between groups. The median (interquartile range) urinary MCP-1 (pg/mg creatinine) was significantly higher in ADPKD patients (185.4 [213.8]) compared with controls (154.7 [98.0], P = 0.010). Human proximal tubular cells with a heterozygous PKD1 mutation and mouse collecting duct cells with a PKD1 knockout exhibited increased MCP-1 secretion. Human fetal ADPKD kidneys displayed prominent MCP-1 immunoreactivity and M2 macrophage infiltration. CONCLUSION: An increase in tubular MCP-1 secretion is an early event in ADPKD. MCP-1 is an early disease severity marker and a potential treatment target.

Has the prevalence of congenital abnormalities after intracytoplasmic sperm injection increased? The Leuven data 1994-2000 and a review of the literature.

BACKGROUND: Although intracytoplasmic sperm injection (ICSI) is now accepted as the treatment of choice for severe male infertility, concerns about its safety and the potential risks for the offspring remain. We reviewed the literature with respect to the prevalence of major congenital malformations after the ICSI technique and supplemented these data with the results of a prospective follow-up study performed in our center. METHODS: From January 1994 till June 2000, 776 ICSI cycles were carried out at the Leuven University Fertility Center. The resulting pregnancies (n = 172) were followed for biochemical and obstetrical parameters, prenatal diagnosis and congenital abnormalities. RESULTS: A total of 134/172 (78%) ongoing pregnancies resulted in 132 deliveries of 166 live born children. Two terminations of pregnancy were carried out due to the presence of major congenital anomalies, diagnosed at prenatal ultrasound. Prenatal diagnosis was carried out in 55 fetuses. Two de novo chromosomal aberrations were found. Major congenital abnormalities were observed at birth in 9/150 (6.0%) children. The total malformation rate was 6.5%. CONCLUSIONS: The prevalence of congenital abnormalities in children born after ICSI in our center (6.5%) was comparable to the prevalence of congenital abnormalities after ICSI reported in the literature.

The ANTENATAL multicentre study to predict postnatal renal outcome in fetuses with posterior urethral valves: objectives and design.

BACKGROUND: Posterior urethral valves (PUV) account for 17% of paediatric end-stage renal disease. A major issue in the management of PUV is prenatal prediction of postnatal renal function. Fetal ultrasound and fetal urine biochemistry are currently employed for this prediction, but clearly lack precision. We previously developed a fetal urine peptide signature that predicted in utero with high precision postnatal renal function in fetuses with PUV. We describe here the objectives and design of the prospective international multicentre ANTENATAL (multicentre validation of a fetal urine peptidome-based classifier to predict postnatal renal function in posterior urethral valves) study, set up to validate this fetal urine peptide signature. METHODS: Participants will be PUV pregnancies enrolled from 2017 to 2021 and followed up until 2023 in >30 European centres endorsed and supported by European reference networks for rare urological disorders (ERN eUROGEN) and rare kidney diseases (ERN ERKNet). The endpoint will be renal/patient survival at 2 years postnatally. Assuming α = 0.05, 1-ß = 0.8 and a mean prevalence of severe renal outcome in PUV individuals of 0.35, 400 patients need to be enrolled to validate the previously reported sensitivity and specificity of the peptide signature. RESULTS: In this largest multicentre study of antenatally detected PUV, we anticipate bringing a novel tool to the clinic. Based on urinary peptides and potentially amended in the future with additional omics traits, this tool will be able to precisely quantify postnatal renal survival in PUV pregnancies. The main limitation of the employed approach is the need for specialized equipment. CONCLUSIONS: Accurate risk assessment in the prenatal period should strongly improve the management of fetuses with PUV.

Pain and bleeding pattern related to levonorgestrel intrauterine system (LNG-IUS) insertion.

OBJECTIVE: To investigate whether the pattern or pain or bleeding during levonorgestrel intrauterine system (LNG-IUS) insertion and in the first 6 weeks thereafter is altered by LNG-IUS malposition. STUDY DESIGN: Prospective cohort of 413 women undergoing LNG-IUS insertion or replacement. A first questionnaire on pain perception was completed by the women immediately after insertion. In a second questionnaire the women were asked to record pain in the 3 days following insertion and both pain and bleeding from 4 to 6 weeks after insertion. Six weeks after insertion a 2D- and 3D-ultrasound examination was performed to evaluate the position of the LNG-IUS and of the uterus. RESULTS: Parity was inversely related to pain at insertion, in the first 3 days and at 4-6 weeks. LNG-IUS insertion was less painful in the postpartum period. Women who had had a LNG-IUS as prior contraceptive method reported a higher percentage of amenorrhea at 4-6 weeks. The position of the LNG-IUS or of the uterus did not influence the pain scores or the bleeding pattern. The fact that the LNG-IUS arms appeared embedded in the uterine wall on coronal 3D-volume reconstruction did not influence pain or the bleeding pattern. CONCLUSIONS: Because neither pain nor bleeding is a reliable predictor of LNG-IUS position, we suggest an ultrasound examination to confirm correct LNG-IUS placement in all patients at about 6 weeks after insertion.

Prospective assessment of fetal cardiac function with speckle tracking in healthy fetuses and recipient fetuses of twin-to-twin transfusion syndrome.

BACKGROUND: The aim of this study was to assess speckle tracking-derived fetal cardiac function in a normal population and in recipient fetuses of twin-to-twin transfusion syndrome (TTTS). METHODS: A case-control study was conducted of 59 uncomplicated singleton pregnancies and 17 recipient fetuses of TTTS. Peak systolic strain, strain rate, velocity, and displacement were calculated, corrected for gestational age, and compared between patients with TTTS and controls. RESULTS: The feasibility of speckle tracking was 83% in controls but only 61% in patients with TTTS. Myocardial velocity and displacement increased over gestation, and regional differences were present within each wall and between walls. Strain and strain rate were stable within each wall but were higher in the right ventricle than in the left ventricle and septum. Right ventricular strain was decreased in patients with TTTS compared with controls (0.75+/-0.34 vs 1.00+/-0.37 multiples of the median, P=.04). CONCLUSION: The feasibility of speckle tracking is low when imaging conditions are challenging, but it can identify right ventricular failure in selected patients with TTTS.