Prenatal parental decision-making and postnatal outcome in renal oligohydramnios

Long-Term Outcomes, Including Fetal and Neonatal Prognosis, of Renal Oligohydramnios: A Retrospective Study over 22 Years

OBJECTIVE

To assess the long-term outcome of renal oligohydramnios and risk factors for fetal, neonatal, and postneonatal death.

STUDY DESIGN

This retrospective cohort study included fetuses with prenatally detected renal oligohydramnios between 2002 and 2023. Patients who were lost to follow-up were excluded. Fetal, neonatal, and long-term outcomes were evaluated, and their risk factors were analyzed.

RESULTS

Of 131 fetuses with renal oligohydramnios, 46 (35%) underwent a termination of pregnancy, 11 (8%) had an intrauterine fetal death, 26 (20%) had a neonatal death, nine (7%) had a postneonatal death, and 39 (30%) survived. Logistic regression analyses showed that an earlier gestational age at onset (OR 1.16, 95% CI 1.01-1.37) was significantly associated with intrauterine fetal death; anhydramnios (OR 12.7, 95% CI 1.52-106.7) was significantly associated with neonatal death as a prenatal factor. Although neonatal survival rates for bilateral renal agenesis, bilateral multicystic dysplastic kidney (MCDK), and unilateral MCDK with contralateral renal agenesis were lower than for other kidney diseases, 1 case of bilateral renal agenesis and two of bilateral MCDK survived with fetal intervention. Kaplan-Meier overall survival rates were 57%, 55%, and 51% for 1, 3, and 5 years, respectively. In the Cox proportional hazards model, birth weight <2000 g (hazard ratio 7.33, 95% CI 1.48-36.1) and gastrointestinal comorbidity (hazard ratio 4.37, 95% CI 1.03-18.5) were significant risk factors for postneonatal death.

CONCLUSION

Long-term survival following renal oligohydramnios is a feasible goal and its appropriate risk assessment is important.

Severe Fetal CAKUT (Congenital Anomalies of the Kidneys and Urinary Tract), Prenatal Consultations, and Initiation of Neonatal Dialysis

INTRODUCTION

Pediatric nephrology prenatal consultations for congenital anomalies of the kidney and urinary tract (CAKUT) and criteria for kidney replacement therapy initiation in neonatal end-stage kidney disease (ESKD) are not well described. We evaluated pediatric nephrology approaches to prenatal CAKUT counseling and neonatal dialysis initiation.

METHODS

A 35-question Qualtrics survey was distributed via the North American Pediatric Renal Trials and Collaborative Studies email list between January and March 2021. Thirty-nine pediatric nephrology centers completed the survey.

RESULTS

All but one responding center (n = 38) provide prenatal CAKUT consultations and neonatal dialysis, with wide variability in reported multispecialty involvement. Nearly half (47%) of centers utilize written/unwritten criteria for offering neonatal dialysis. The most common contraindications to neonatal dialysis were parental refusal (61%), contraindication to access placement by surgeons (55%), and birth weight (BW) contraindication (55%, with < 1,500 g being the most common BW contraindication). Overall, 79% of centers reported caring for < 5 neonates with ESKD in the past year, 61% use hemodialysis therapies prior to peritoneal dialysis in neonates requiring dialysis, and 100% transition to peritoneal dialysis by hospital discharge.

CONCLUSION

Many pediatric nephrology programs provide prenatal CAKUT consultations and neonatal dialysis, but with variability in practice approach. Further multicenter research regarding prenatal consultations and neonatal dialysis outcomes is necessary to further improve care delivery to this population.

Amniotic fluid content in children with kidney and urinary tract anomalies determines pre- and postnatal development

BACKGROUND

Renal oligohydramnios (ROH) describes an abnormally low volume of amniotic fluid (AF) during pregnancy. ROH is mostly caused by congenital fetal kidney anomalies. The ROH diagnosis frequently implies an increased risk of peri- and postnatal fetal mortality and morbidity. The present study aimed to evaluate the impact of ROH on pre-and postnatal development in children with congenital kidney anomalies.

METHODS

This retrospective study included 168 fetuses with anomalies in the kidney and urinary tract. Based on the amount of AF measured by ultrasound, patients were divided into three groups: normal amniotic fluid (NAF), amniotic fluid in the lower normal range (LAF), and ROH. These groups were compared with respect to prenatal sonographic parameters, perinatal outcomes, and postnatal outcomes.

RESULTS

Among the 168 patients with congenital kidney anomalies, 26 (15%) had ROH, 132 (79%) had NAF, and 10 (6%) had LAF. Of the 26 families affected by ROH, 14 (54%) decided to terminate pregnancy. Of 10 live-born children in the ROH group, 6 (60%) survived the observation time; of these, 5/6 presented with chronic kidney disease, stages I-III, at their last examination. The main differences in postnatal development between the ROH group and the NAF and LAF groups were: restricted height and weight gain, respiratory issues, complicated feeding, and the presence of extrarenal malformations.

CONCLUSIONS

ROH is not a mandatory indicator of severe postnatal kidney function impairment. However, children with ROH have complicated peri-and postnatal periods, due to the presence of concomitant malformations, which must be considered in prenatal care. A higher resolution version of the Graphical abstract is available as Supplementary information.

Predictive factors for survival in patients with oligohydramnios secondary to antenatal kidney disease

BACKGROUND

Renal oligohydramnios (ROH) is caused by bilateral congenital abnormalities, either of renal parenchymal or obstructive origin. ROH is a poor prognostic factor of neonatal survival; lung hypoplasia is reported to be the main cause of mortality. We aimed to describe the fetal morbidity and pre- and postnatal mortality in case of ROH due to renal congenital pathologies and to find predictive risk factors for morbidity and mortality.

METHODS

All data were collected in Trousseau Hospital in the obstetric, neonatology, and pediatric nephrology units, from 2008 to 2020.

RESULTS

We included 66 fetuses with renal parenchymal pathologies posterior urethral valves (PUV) (N = 25), bilateral kidney agenesis (N = 10), hypodysplasia (N = 16), and polycystic kidney disease (N = 10) causing oligohydramnios identified on antenatal ultrasound. Total pre- and postnatal mortality was 76% (50/66). Mortality, excepting termination of pregnancy (TOP), was 65%. The presence of pneumomediastinum and pneumothorax was not different in survivors and non-survivors. Fetuses with kidneys having features of hypodysplasia on ultrasound at T2 and those with oligohydramnios before 32 weeks GA had a higher risk of death. There was a significant difference in plasma creatinine of the surviving patients compared to the deceased patients, from day 3 onwards (183 µmol/L [88; 255] vs. 295 µmol/L [247; 326]; p = 0.038).

CONCLUSIONS

The main differences between survivors and non-survivors among patients with "renal oligohydramnios" were oligohydramnios detection before 32 weeks GA, dysplasia detection on the second trimester ultrasound, and increase of serum creatinine from day 3 onwards. A higher resolution version of the Graphical abstract is available as Supplementary information.

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-β4. 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-β4 abundance was confirmed with ELISA. Knockout of thymosin-β4 in zebrafish altered proximal and distal tubule pronephros growth suggesting a possible role of thymosin β4 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.

[Kidney Cysts and Cystic Nephropathies in Children - A Consensus Guideline by 10 German Medical Societies]

This consensus-based guideline was developed by all relevant German pediatric medical societies. Ultrasound is the standard imaging modality for pre- and postnatal kidney cysts and should also exclude extrarenal manifestations in the abdomen and internal genital organs. MRI has selected indications. Suspicion of a cystic kidney disease should prompt consultation of a pediatric nephrologist. Prenatal management must be tailored to very different degrees of disease severity. After renal oligohydramnios, we recommend delivery in a perinatal center. Neonates should not be denied renal replacement therapy solely because of their age. Children with unilateral multicystic dysplastic kidney do not require routine further imaging or nephrectomy, but long-term nephrology follow-up (as do children with uni- or bilateral kidney hypo-/dysplasia with cysts). ARPKD (autosomal recessive polycystic kidney disease), nephronophthisis, Bardet-Biedl syndrome and HNF1B mutations cause relevant extrarenal disease and genetic testing is advisable. Children with tuberous sclerosis complex, tumor predisposition (e. g. von Hippel Lindau syndrome) or high risk of acquired kidney cysts should have regular ultrasounds. Even asymptomatic children of parents with ADPKD (autosomal dominant PKD) should be monitored for hypertension and proteinuria. Presymptomatic diagnostic ultrasound or genetic examination for ADPKD in minors should only be done after thorough counselling. Simple cysts are very rare in children and ADPKD in a parent should be excluded. Complex renal cysts require further investigation.

End-stage kidney disease in infancy: an educational review

An increasing number of infants with end-stage kidney disease (ESKD) are surviving and receiving renal replacement therapy (RRT). Unique clinical issues specific to this age group of patients influence their short- and long-term outcomes. This review summarizes current epidemiology, clinical characteristics, ethical dilemmas, management concerns, and outcomes of infants requiring chronic dialysis therapy. Optimal care during infancy requires a multidisciplinary team working closely with the patient's family. Nutritional management, infection prevention, and attention to cardiovascular status are important treatment targets. Although mortality rates remain higher among infants on dialysis compared to older pediatric dialysis patients, outcomes have improved over time. Most importantly, infants who subsequently receive a kidney transplant are now experiencing graft survival rates that are comparable to older pediatric patients.