Successful in utero intervention for bilateral renal agenesis

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.

MR Imaging of the Fetal Genitourinary Tract

Fetal MR imaging overcomes many of the technical barriers of ultrasound and is an important diagnostic tool for fetal genitourinary (GU) anomalies. It is suited for evaluation of GU anomalies because of the fluid-sensitive sequences and superior soft tissue contrast. Often GU malformations are part of a multisystem genetic or congenital condition, and imaging the entire fetus with MR adds additional clarity about the extent of disease. It adds confidence to diagnoses of renal agenesis, urinary tract dilation, cystic disease, and tumors. It is particularly useful to delineate anatomy in complex GU malformations. This additional information guides counseling.

Bilateral renal agenesis: fetal intervention and outcomes

Bilateral renal agenesis (BRA) is a fetal anomaly which leads to anhydramnios and resultant pulmonary hypoplasia. Historically, this anomaly was universally fatal early in the neonatal period due to the severity of the associated lung disease. Over the last 30 years, innovations in fetal therapies-specifically, serial amnioinfusions-have led to instances of infant pulmonary survival and initiation of postnatal dialysis, raising the possibility that early neonatal death may not be inevitable. Amnioinfusions are not without risk, and maternal complications can include prelabor rupture of membranes, preterm labor, infection, and bleeding. The data detailing neonatal outcomes are still limited and actively being collected. Two case series and one non-randomized clinical trial have supplied most of the known outcome data for infants with BRA after prenatal amnioinfusion. Although there are survivors reported in the literature, mortality remains high, with many deaths in infancy due to dialysis-associated sepsis. In addition, previously unknown morbidities have been documented in these infants, including neurologic injury. These challenges, in addition to the mechanical difficulties of providing dialysis to extremely small infants, can result in significant burdens for patients and their caregivers and moral distress for the health care team. The present review aims to explain the pathophysiology of BRA, detail the historical context and rationale for serial amnioinfusions to treat the pulmonary insufficiency associated with BRA, describe the available data regarding outcomes of infants born following prenatal amnioinfusions, discuss ethical issues surrounding this fetal intervention, and describe critical aspects of prenatal counseling for patients considering the intervention.

Prenatal delivery of a therapeutic antisense oligonucleotide achieves broad biodistribution in the brain and ameliorates Angelman syndrome phenotype in mice

Angelman syndrome (AS), an early-onset neurodevelopmental disorder characterized by abnormal gait, intellectual disabilities, and seizures, occurs when the maternal allele of the UBE3A gene is disrupted, since the paternal allele is silenced in neurons by the UBE3A antisense (UBE3A-AS) transcript. Given the importance of early treatment, we hypothesized that prenatal delivery of an antisense oligonucleotide (ASO) would downregulate the murine Ube3a-AS, resulting in increased UBE3A protein and functional rescue. Using a mouse model with a Ube3a-YFP allele that reports on-target ASO activity, we found that in utero, intracranial (IC) injection of the ASO resulted in dose-dependent activation of paternal Ube3a, with broad biodistribution. Accordingly, in utero injection of the ASO in a mouse model of AS also resulted in successful restoration of UBE3A and phenotypic improvements in treated mice on the accelerating rotarod and fear conditioning. Strikingly, even intra-amniotic (IA) injection resulted in systemic biodistribution and high levels of UBE3A reactivation throughout the brain. These findings offer a novel strategy for early treatment of AS using an ASO, with two potential routes of administration in the prenatal window. Beyond AS, successful delivery of a therapeutic ASO into neurons has implications for a clinically feasible prenatal treatment for numerous neurodevelopmental disorders.

Survey of Neonatal Management After Amnioinfusion for Anhydramnios

This survey study reports on use of renal replacement therapy, hemodynamic support, sedation, neuroimaging, and extracorporeal membrane oxygenation at Renal Anhydramnios Fetal Therapy trial sites for neonates with either bilateral renal agenesis or fetal kidney failure.

Precarious hope: Ethical considerations for offering experimental fetal therapies outside of research after initial studies in humans

OBJECTIVE

Risks and benefits of experimental fetal therapies can remain uncertain after initial clinical studies, especially long-term effects. Nevertheless, pregnant individuals may request them, hoping to benefit their future child. Guidance about offering experimental fetal therapies outside research (as "innovative therapy") is limited, despite their ethical complexity. We propose points for clinicians and reviewers to consider when deciding whether and how to offer experimental fetal therapies as innovative therapies after initial clinical studies.

METHOD

We used conceptual analysis and a current case to develop points for consideration, grounded in broader debates on innovative therapy and the unique challenges associated with experimental fetal therapies.

RESULTS

Clinicians should evaluate whether offering experimental fetal therapies as innovative therapy is appropriate for a pregnant individual and their fetus. The anticipated risk-benefit ratio for the fetus should be favorable. For the pregnant individual, risks may outweigh benefits, within reasonable limits. Medical resources should be sufficient to ensure appropriate care. Clinicians should support pregnant individuals in making informed choices. Clinicians offering innovative therapies with more than minimal risk should collect and report data on outcomes. Independent review should take place.

CONCLUSION

Considering these points may advance the interests of fetuses, future children, and their families.

Angiotensin-II Use for Refractory Hypotension in an Infant With Bilateral Renal Agenesis

Infants with congenital bilateral renal agenesis are at significant risk for morbidity and mortality, despite substantial and continuing advances in fetal and neonatal therapeutics. Infants with bilateral renal agenesis may episodically develop severe hypotension that can be refractory to traditional vasopressors. Synthetic angiotensin-II has been successfully used in adult and a few pediatric patients with refractory hypotension but has not been extensively studied in infants. We describe the use of angiotensin-II in treating refractory hypotension in a premature infant with congenital bilateral renal agenesis admitted to the NICU. Within 48 hours, he no longer required other vasopressors. Subsequently, angiotensin-II was gradually weaned and discontinued over 10 days and the patient was ultimately discharged from the hospital. This case demonstrates that angiotensin-II may be a helpful agent to treat refractory hypotension in infants with bilateral renal agenesis.

Neonatal Survival After Serial Amnioinfusions for Bilateral Renal Agenesis: The Renal Anhydramnios Fetal Therapy Trial

Importance

Early anhydramnios during pregnancy, resulting from fetal bilateral renal agenesis, causes lethal pulmonary hypoplasia in neonates. Restoring amniotic fluid via serial amnioinfusions may promote lung development, enabling survival.

Objective

To assess neonatal outcomes of serial amnioinfusions initiated before 26 weeks' gestation to mitigate lethal pulmonary hypoplasia.

Design, Setting, and Participants

Prospective, nonrandomized clinical trial conducted at 9 US fetal therapy centers between December 2018 and July 2022. Outcomes are reported for 21 maternal-fetal pairs with confirmed anhydramnios due to isolated fetal bilateral renal agenesis without other identified congenital anomalies.

Exposure

Enrolled participants initiated ultrasound-guided percutaneous amnioinfusions of isotonic fluid before 26 weeks' gestation, with frequency of infusions individualized to maintain normal amniotic fluid levels for gestational age.

Main Outcomes and Measures

The primary end point was postnatal infant survival to 14 days of life or longer with dialysis access placement.

Results

The trial was stopped early based on an interim analysis of 18 maternal-fetal pairs given concern about neonatal morbidity and mortality beyond the primary end point despite demonstration of the efficacy of the intervention. There were 17 live births (94%), with a median gestational age at delivery of 32 weeks, 4 days (IQR, 32-34 weeks). All participants delivered prior to 37 weeks' gestation. The primary outcome was achieved in 14 (82%) of 17 live-born infants (95% CI, 44%-99%). Factors associated with survival to the primary outcome included a higher number of amnioinfusions (P = .01), gestational age greater than 32 weeks (P = .005), and higher birth weight (P = .03). Only 6 (35%) of the 17 neonates born alive survived to hospital discharge while receiving peritoneal dialysis at a median age of 24 weeks of life (range, 12-32 weeks).

Conclusions and Relevance

Serial amnioinfusions mitigated lethal pulmonary hypoplasia but were associated with preterm delivery. The lower rate of survival to discharge highlights the additional mortality burden independent of lung function. Additional long-term data are needed to fully characterize the outcomes in surviving neonates and assess the morbidity and mortality burden.

Trial Registration

ClinicalTrials.gov Identifier: NCT03101891.

Clinical assessment of the fetal right Quantitative Lung Index

OBJECTIVES

We have previously described gestational-age-independent sonographic indices to assess fetal lung size in the right and left lungs: The Quantitative Lung Index for the right lung (QLI-R) and for the left lung (QLI-L), respectively. The purpose of this study was to evaluate the clinical cutoff point of the QLI-R to predict pulmonary hypoplasia and neonatal death.

MATERIALS AND METHODS

Retrospective assessment of the QLI-R in patients with left-sided congenital diaphragmatic hernia (CDH-L) and other fetal conditions at risk for fetal pulmonary hypoplasia. Cross-section and longitudinal assessment of the behavior of the QLI-R in untreated and treated patients. ROC curve analysis to determine the optimal cutoff point of the QLI-R in predicting neonatal death.

RESULTS

One hundred eighteen patients with CDH-L and other fetal conditions at risk for pulmonary hypoplasia had QLI-R measurements done. Seventeen patients were excluded for various reasons. Eleven patients with conditions other than CDH-L but at risk for pulmonary hypoplasia were used for intraclass coefficient measurements of the QLI-R. Ninety patients had CDH-L, of which 78 did not undergo antenatal intervention and in which the cutoff point for pulmonary hypoplasia and neonatal demise was assessed. Stent tracheal occlusion was performed in the remaining 12 patients with CDH-L, in which the behavior of the QLI after surgery was assessed. Analysis of the ICC showed an overall intra-rater reliability of 0.985 (Cronbach's Alpha-based). There was no correlation between gestational age and QLI-R (-0.73, Pearson correlation, p = .72). Twenty-six of the 78 patients (33%) with CDH-L managed expectantly had a neonatal demise. A QLI-R equal to or less than 0.45 was significantly predictive of neonatal demise (area under the curve 0.64, p = .046, sensitivity 77%). Nine of the 12 patients (75%) that underwent tracheal occlusion had neonatal survival. Of these, 10 had serial assessments of the QLI-R after surgery. An increase in the QLI-R of 0.11 was associated with a tendency for neonatal survival (p = .056).

CONCLUSION

Our study confirms that the QLI-R is a gestational-age-independent measurement of fetal lung size, with a high degree of reproducibility. In a population of expectantly managed CDH-L patients, a cutoff value of the QLI-R of 0.45 or lower is predictive of neonatal death from pulmonary hypoplasia. The QLI-R can be used to monitor fetal lung growth after tracheal occlusion, and an increase in the QLI-R is suggestive of neonatal survival. Further prospective studies are needed to confirm these findings and to explore the use of the QLI in other populations at risk for pulmonary hypoplasia and consequent neonatal demise.

Modeling Podocyte Ontogeny and Podocytopathies with the Zebrafish

Podocytes are exquisitely fashioned kidney cells that serve an essential role in the process of blood filtration. Congenital malformation or damage to podocytes has dire consequences and initiates a cascade of pathological changes leading to renal disease states known as podocytopathies. In addition, animal models have been integral to discovering the molecular pathways that direct the development of podocytes. In this review, we explore how researchers have used the zebrafish to illuminate new insights about the processes of podocyte ontogeny, model podocytopathies, and create opportunities to discover future therapies.

Fetal Therapy for Renal Anhydramnios

The most severe forms of congenital anomalies of the kidney and urinary tract present in fetal life with early pregnancy renal anhydramnios and are considered lethal due to pulmonary hypoplasia without fetal therapy. Due to the high rate of additional structural anomalies, genetic abnormalities, and associated syndromes, detailed anatomic survey and genetic testing are imperative when stratifying which pregnancies are appropriate for fetal intervention. Restoring amniotic fluid around the fetus is the principal goal of prenatal treatment. The ongoing multi-center Renal Anhydramnios Fetal Therapy (RAFT) trial is assessing the safety and efficacy of serial amnioinfusions to prevent pulmonary hypoplasia so that the underlying renal disease can be addressed.

Design and Protocol of the Renal Anhydramnios Fetal Therapy (RAFT) Trial

PURPOSE

Anhydramnios secondary to anuria before 22 weeks of gestational age and congenital bilateral renal agenesis before 26 weeks of gestational age are collectively referred to as early-pregnancy renal anhydramnios. Early-pregnancy renal anhydramnios occurs in at least 1 in 2000 pregnancies and is considered universally fatal when left untreated because of severe pulmonary hypoplasia precluding ex utero survival The Renal Anhydramnios Fetal Therapy (RAFT) trial is a nonrandomized, nonblinded, multicenter clinical trial designed to assess the efficacy, safety, and feasibility of amnioinfusions for patients with pregnancies complicated by early-pregnancy renal anhydramnios. The primary objective of this study is to determine the proportion of neonates surviving to successful dialysis, defined as use of a dialysis catheter for ≥14 days.

METHODS

A consortium of 9 North American Fetal Therapy Network (NAFTNet) centers was formed, and the RAFT protocol was refined in collaboration with the NAFTNet Scientific Committee. Enrollment in the trial began in April 2020. Participants may elect to receive amnioinfusions or to join the nonintervention observational expectant management group. Eligible pregnant women must be at least 18 years of age with a fetal diagnosis of isolated early-pregnancy renal anhydramnios.

FINDINGS

In addition to the primary study objective stated above, secondary objectives include (1) to assess maternal safety and feasibility of the serial amnioinfusion intervention (2) to perform an exploratory study of the natural history of untreated early pregnancy renal anhydramnios (3) to examine correlations between prenatal imaging and lung specific factors in amniotic fluid as predictive of the efficacy of serial percutaneous amnioinfusions and (4) to determine short- and long-term outcomes and quality of life in surviving neonates and families enrolled in RAFT IMPLICATIONS: The RAFT trial is the first clinical trial to investigate the efficacy, safety, and feasibility of amnioinfusions to treat the survival-limiting pulmonary hypoplasia associated with anhydramnios. Although the intervention offers an opportunity to treat a condition known to be almost universally fatal in affected neonates, the potential burdens associated with end-stage kidney disease from birth must be acknowledged.

CLINICALTRIALS

gov identifier: NCT03101891.

Outcomes of dialysis in neonates with anuric end-stage renal disease at birth: ethical considerations

INTRODUCTION

We present a case series of neonates with anuric ESRD undergoing renal replacement therapy (RRT) and discuss the associated ethical implications of RRT in this population.

METHODS

We reviewed patients who initiated RRT within 1 week of life due to anuric ESRD from 2009-2019 at a single tertiary center. Primary outcomes were receipt of renal transplant (RT), one-year survival, and overall survival.

RESULTS

Five patients met the inclusion criteria. Two patients received an RT. One-year survival was 80%, while overall survival was 60% with a median follow-up of 18 months. In the 2 still-living patients who have not undergone RT, they are ineligible, one due to recent malignancy and the other from acquired cardiovascular comorbidities.

CONCLUSION

Patients with anuric ESRD requiring RRT undergo multiple treatment challenges with low RT and survival rates. These findings should be shared with families considering intervention for cases of severe renal disease diagnosed prenatally.

Prenatally diagnosed posterior urethral valves: ethical dilemmas of fetal intervention

Although anhydramnios due to in utero renal failure has traditionally been considered lethal, in utero interventions offer the potential for pulmonary survival. As fetal interventions become more common, questions arise about how to identify and counsel eligible candidates.  In this report we describe the presentation and management of a 17-year-old pregnant female who presented from out-of-state with severe lower urinary tract obstruction (LUTO) with associated anhydramnios, focusing on the ethical questions that this case raised.

Pulmonary hypoplasia correlates with the length of anhydramnios in patients with early pregnancy renal anhydramnios (EPRA)

BACKGROUND

Early pregnancy renal anhydramanios (EPRA) occurs when the fetus is anuric before 22 weeks gestational age (GA) and is considered universally lethal. Serial amnioinfusions have successfully ameliorated the lethal pulmonary hypoplasia associated with EPRA and have resulted in cases of neonatal survival, peritoneal dialysis, and renal transplant.

OBJECTIVE

We sought to evaluate the lung pathology of untreated fetuses and neonates that had EPRA.

STUDY DESIGN

This is a retrospective case series of all fetuses and neonates diagnosed with isolated EPRA that underwent autopsy at a single tertiary care center between 1987 and 2018. Autopsy data were correlated with ultrasound findings and GA at delivery. Fetal weights, lung weights, and lung developmental stage were recorded.

RESULTS

Nineteen cases met criteria for analysis and ranged from 16 to 38 weeks GA at termination or birth. The observed-to-expected (O/E) lung-to-body-weight ratio was significantly associated with GA (r = -0.51, p = 0.03), such that as GA increased the O/E ratio decreased. When limited to patients >22 weeks, this relationship strengthened (r = -0.75, p = 0.01). Importantly, overall O/E body weight had no relationship with GA.

CONCLUSION

This study shows that the degree of pulmonary hypoplasia in EPRA increases with the length of anhydramnios. This suggests that amnioinfusions are likely to be of most benefit the soonest they can feasibly be initiated.

Novel Approach for Laparoscopically Placed Chronic Amniotic Fluid Catheters in Sheep

INTRODUCTION

Several fetal therapies involve repeated amniotic fluid intervention. We hypothesize that a minimally invasive approach can be used to safely implant an intrauterine catheter infusion system in a fetal ovine model for chronic use during pregnancy.

METHOD

Five pregnant sheep underwent operation between gestational days 110 and 115 (term 145 days). A Codman® implantable infusion pump was adapted for intrauterine use. The chamber was placed in the maternal flank and the tunneled catheter laparoscopically inserted into the amniotic cavity, secured with a pursestring. Three had an additional uterine anchoring suture. Ewes were sacrificed after natural delivery, and the uterus underwent gross and microscopic analyses.

RESULTS

There were no maternal mortalities, abortions, or preterm labor. Pumps were accessed and remained functional throughout gestation. Four ewes delivered healthy term lambs; the other delivered twins with failure to progress and demise. On necropsy, catheters secured with an anchoring suture remained in place, while the other 2 dislodged during labor. There was no chorioamnionitis by culture or histology.

CONCLUSION

Laparoscopically placed intra-amniotic infusion catheters were implanted safely and remained functional until delivery in an ovine model. This novel approach has promise in providing safe, durable amniotic fluid access for the potential treatment of fetal disease.

Fetal interventions for congenital renal anomalies

Congenital abnormalities of the kidney and urinary tract (CAKUT) represent 20% of prenatally diagnosed congenital abnormalities. Although the majority of these abnormalities do not require intervention either pre or postnatally, there is a subset of patients whose disease is so severe that it may warrant intervention prior to delivery to prevent morbidity and mortality. These cases consist of patients with moderate lower urinary tract obstruction (LUTO) in which vesicocentesis, shunting or cystoscopy are options and patients with early pregnancy renal anhydramnios (EPRA) in whom amnioinfusion therapy may be an option. The main causes of EPRA are congenital bilateral renal agenesis (CoBRA), cystic kidney disease (CKD) and severe LUTO. Untreated, EPRA is universally fatal secondary to anhydramnios induced pulmonary hypoplasia. The evidence regarding therapy for LUTO is limited and the stopped early PLUTO (Percutaneous Shunting in Lower Urinary Tract Obstruction) trial was unable to provide definitive answers about patient selection. Evidence for EPRA therapy is also scant. Serial amnioinfusions have shown promise in cases of EPRA due to CoBRA or renal failure and this treatment modality forms the basis of the ongoing NIH funded RAFT (Renal Anhydramnios Fetal Therapy) trial. At present, there is consensus that treatment for EPRA should only occur in the setting of a clinical trial.

Management of antenatal hydronephrosis

Antenatal hydronephrosis (AHN) is the most frequently detected abnormality by prenatal ultrasonography. Differential diagnosis of AHN includes a wide variety of congenital abnormalities of the kidney and urinary tract ranging from mild abnormalities such as transient or isolated AHN to more important ones as high-grade congenital vesicoureteral reflux or ureteropelvic junction obstruction. It is well known that the outcome depends on the underlying etiology. Various grading systems have been proposed for the classification of AHN on prenatal and postnatal ultrasonography. Mild isolated AHN represents up to 80% of cases, is considered to be benign, and majority of them resolve, stabilize, or improve during follow-up. Controversies exist regarding the diagnosis and management of some important and severe causes of AHN such as high-grade vesicoureteral reflux and ureteropelvic junction obstruction. Current approach is becoming increasingly conservative during diagnosis and follow-up of these patients with less imaging and close follow-up. However, there is still no consensus regarding the clinical significance, postnatal evaluation, and management of infants with AHN. The aim of this review is to discuss the controversies and provide an overview on the management of AHN.

Obstetric complications in pregnancies with life-limiting malformations

PURPOSE OF REVIEW

The implementation of palliative care at birth has led to a significant rise in the number of couples who choose to continue with pregnancies complicated by life-limiting malformations (LLMs). Prenatal counselling and appropriate antenatal/perinatal management in these cases are poorly studied and may pose significant challenges. The purpose of this review is to outline specific obstetric risks and to suggest management for mothers who choose to continue with pregnancies with the most common LLMs.

RECENT FINDINGS

In pregnancies complicated by LLMs where parents opt for expectant management, clinicians should respect parental wishes, whilst openly sharing potential serious maternal medical risks specific for the identified abnormalities. The focus of both antenatal and perinatal care should be maternal wellbeing rather than foetal survival. Follow-up ultrasound examinations and maternal surveillance should be aimed at achieving timely diagnosis and effective management of obstetric complications. A clear perinatal plan, agreed with the couples by a multi-disciplinary team including a foetal medicine specialist, a neonatologist and a geneticist, is crucial to reduce maternal morbidity.

SUMMARY

This review provides a useful framework for clinicians who face the challenges of counselling and managing cases complicated by LLMs where parents opt for pregnancy continuation.

Serial Amnioinfusion as Regenerative Therapy for Pulmonary Hypoplasia in Fetuses With Intrauterine Renal Failure or Severe Renal Anomalies: Systematic Review and Future Perspectives

The aim of this study was to investigate the effect of serial amnioinfusion therapy (SAT) for pulmonary hypoplasia in lower urinary tract obstruction (LUTO) or congenital renal anomalies (CRAs), introduce patient selection criteria, and present a case of SAT in bilateral renal agenesis. We conducted a search of the MEDLINE, EMBASE, Web of Science, and Scopus databases for articles published from database inception to November 10, 2017. Eight studies with 17 patients (7 LUTO, 8 CRA, and 2 LUTO + CRA) were included in the study. The median age of the mothers was 31 years (N=9; interquartile range [IQR], 29-33.5 years), the number of amnioinfusions was 7 (N=17; IQR, 4.5-21), gestational age at first amnioinfusion was 23 weeks and 4 days (N=17; IQR, 21-24.07), gestational age at delivery was 32 weeks and 2 days (N=17; IQR, 30 weeks to 35 weeks and 6.5 days), birthweight of newborns was 3.7 kg (N= 9; IQR, 2.7-3.7 kg), Apgar score at 1 minute was 2.5 (N=8; IQR, 1-6.5), and Apgar score at 5 minutes was 5.5 (N=8; IQR, 0-7.75). In conclusion, SAT may provide fetal pulmonary palliation by reducing the risk of newborn pulmonary compromise secondary to oligohydramnios. Multidisciplinary research efforts are required to further inform treatment and counseling guidelines. We propose a multidisciplinary approach to prenatal classification of fetuses with LUTO to inform patient selection.

Prenatal regenerative fetoscopic interventions for congenital anomalies

Fetal intervention has progressed in the past two decades from experimental proof-of-concept to practice-adopted, life saving interventions in human fetuses with congenital anomalies. This progress is informed by advances in innovative research, prenatal diagnosis, and fetal surgical techniques. Invasive open hysterotomy, associated with notable maternal-fetal risks, is steadily replaced by less invasive fetoscopic alternatives. A better understanding of the natural history and pathophysiology of congenital diseases has advanced the prenatal regenerative paradigm. By altering the natural course of disease through regrowth or redevelopment of malformed fetal organs, prenatal regenerative medicine has transformed maternal-fetal care. This review discusses the uses of regenerative medicine in the prenatal diagnosis and management of three congenital diseases: congenital diaphragmatic hernia, lower urinary tract obstruction, and spina bifida.

Contemporary Outcomes of Patients with Isolated Bilateral Renal Agenesis with and without Fetal Intervention

INTRODUCTION

Bilateral renal agenesis (BRA) is a lethal diagnosis, specifically meaning that natural survival beyond birth is not expected secondary to pulmonary hypoplasia. Limited contemporary data are available about intervention and the impact of restoring amniotic fluid volume in relation to the risk for lethal pulmonary hypoplasia and other factors that might influence survival in cases of fetal BRA.

OBJECTIVE

We report the largest series of patients undergoing fetal intervention and postnatal care for BRA at a single comprehensive fetal center.

METHODS

All patients with fetal BRA were reviewed from January 2004 to November 2017. Maternal and neonatal data were collected in an institutional review board-approved retrospective review.

RESULTS

From 2014 to 2017, 20 singleton pregnancies with isolated fetal BRA were evaluated and 14 had amnioinfusion. Eight had serial infusions. Of those, there were 6 neonatal deaths. There were 2 neonatal survivors beyond 30 days; however, both died of sepsis on dialysis. One of these survivors received amnioinfusions by percutaneous approach and one via amnioport. There were no survivors to transplantation.

CONCLUSION

Fetal intervention via amnioinfusion may promote pulmonary survivorship after birth, but postnatal survival remains poor. Future studies must place an emphasis on standardizing the postnatal approach to this patient population.

Discordance for Potter's Syndrome in a Dichorionic Diamniotic Twin Pregnancy-An Unusual Case Report

INTRODUCTION

Potter's syndrome, also known as Potter's sequence, is an uncommon and fatal disorder. Potter's sequence in a multiple pregnancy is uncommon, and its frequency remains unknown. Worldwide in a diamniotic twin pregnancy, there are only a few cases described.

CASE REPORT

We present an unusual case discordance for Potter's syndrome in a dichorionic diamniotic twin pregnancy. Twin A had the typical physical and histological Potter's findings. Twin B had normal respiratory function and normal physical examination findings. There are many controversies about this condition in diamniotic twin pregnancy. One case report concluded that that the presence of a normal co-twin in diamniotic pregnancy prevented the cutaneous features seen in Potter's syndrome and ameliorated the pulmonary complications, whereas two other case studies reported that the affected twin had extrarenal features typical of the syndrome.

CONCLUSION

We performed an autopsy and calculated lung weight/body weight ratio to diagnose pulmonary hypoplasia. Histopathologic examination of lungs and kidneys was performed. We concluded that the appearance of extrarenal features in the affected twin depends on the amniocity.

Etiology and management of early pregnancy renal anhydramnios: Is there a place for serial amnioinfusions?

Early pregnancy renal anhydramios (EPRA) comprises congenital renal disease that results in fetal anhydramnios by 22 weeks of gestation. It occurs in over 1 in 2000 pregnancies and affects 1500 families in the US annually. EPRA was historically considered universally fatal due to associated pulmonary hypoplasia and neonatal respiratory failure. There are several etiologies of fetal renal failure that result in EPRA including bilateral renal agenesis, cystic kidney disease, and lower urinary tract obstruction. Appropriate sonographic evaluation is required to arrive at the appropriate urogenital diagnosis and to identify additional anomalies that allude to a specific genetic diagnosis. Genetic evaluation variably includes karyotype, microarray, targeted gene testing, panels, or whole exome sequencing depending on presentation. Patients receiving a fetal diagnosis of EPRA should be offered management options of pregnancy termination or perinatal palliative care, with the option of serial amnioinfusion therapy offered on a research basis. Preliminary data from case reports demonstrate an association between serial amnioinfusion therapy and short-term postnatal survival of EPRA, with excellent respiratory function in the neonatal period. A multicenter trial, the renal anhydramnios fetal therapy (RAFT) trial, is underway. We sought to review the initial diagnosis ultrasound findings, genetic etiologies, and current management options for EPRA.

Two infants with bilateral renal agenesis who were bridged by chronic peritoneal dialysis to kidney transplantation

Bilateral renal agenesis is associated with severe oligohydramnios and was considered incompatible with postnatal life due to severe pulmonary hypoplasia. The use of renal replacement therapy was limited by significant morbidity and mortality associated with dialysis in very young infants with major pulmonary pathology. In the United States, there is a tremendous controversy about whether or not the use of prenatal amniotic fluid infusions provides a benefit to fetuses with bilateral renal agenesis. One of the critical issues identified is that there are, as yet, no children reported who had achieved long-term survival. Previous reports all indicated these children died shortly after birth or after unsuccessful peritoneal dialysis. We present two infants with a prenatal diagnosis of bilateral renal agenesis whose mothers elected to undergo prenatal amnioinfusions. One was born at 28 weeks with a birthweight of 1230 g and the other born at 34 weeks with a birthweight of 1940 g. We present the details of both cases, with initial management on chronic peritoneal dialysis, which started shortly after birth, as a bridge to living related kidney transplants.

Prenatal genetic considerations of congenital anomalies of the kidney and urinary tract (CAKUT)

Congenital anomalies of the kidney and urinary tract (CAKUT) constitute 20% of all congenital malformations occurring in one in 500 live births. Worldwide, CAKUT are responsible for 40% to 50% of pediatric and 7% of adult end-stage renal disease. Pathogenic variants in genes causing CAKUT include monogenic diseases such as polycystic kidney disease and ciliopathies, as well as syndromes that include isolated kidney disease in conjunction with other abnormalities. Prenatal diagnosis most often occurs using ultrasonography; however, further genetic diagnosis may be made using a variety of testing strategies. Family history and pathologic examination can also provide information to improve the ability to make a prenatal diagnosis of CAKUT. Here, we provide a comprehensive overview of genetic considerations in the prenatal diagnosis of CAKUT disorders. Specifically, we discuss monogenic causes of CAKUT, associated ultrasound characteristics, and considerations for genetic diagnosis, antenatal care, and postnatal care.

Uncovering new physiology in bilateral renal agenesis following amnioinfusion

Background

Bilateral renal agenesis has uniformly been a lethal diagnosis in the perinatal or neonatal period. With the advent of more advanced renal replacement therapy as a bridge to renal transplantation, amnioinfusion has been explored at our center as a way to prevent lethal pulmonary hypoplasia secondary to oligohydramnios.

Case presentation

We describe two cases of bilateral renal agenesis with serial amnioinfusion during pregnancy. The families opted for full neonatal intervention and post-natal renal support. While lethal pulmonary hypoplasia was avoided, early and refractory hypotension limited the ability to perform dialysis in these neonates.

Conclusions

Our limited experience shows that barriers to care such as lethal respiratory failure and technical limitations of early dialysis are not the only barriers prohibiting care for this population.

Amnioinfusions to Treat Early Onset Anhydramnios Caused by Renal Anomalies: Background and Rationale for the Renal Anhydramnios Fetal Therapy Trial

Anhydramnios caused by early anuria is thought to be universally fatal due to pulmonary hypoplasia. Bilateral renal agenesis and early fetal renal failure leading to anhydramnios constitute early pregnancy renal anhydramnios (EPRA). There have been successful reports of amnioinfusions to promote lung growth in the setting of EPRA. Some of these successfully treated EPRA fetuses have survived the neonatal period, undergone successful dialysis, and subsequently received a kidney transplant. Conversely, there are no reports of untreated EPRA survivors. This early success of amnioinfusions to treat EPRA justifies a rigorous prospective trial. The objective of this study is to provide a review of what is known about fetal therapy for EPRA and describe the Renal Anhydramnios Fetal Therapy trial. We review the epidemiology, pathophysiology, and genetics of EPRA. Furthermore, we have performed systematic review of case reports of treated EPRA. We describe the ethical framework, logistical challenges, and rationale for the current single center (NCT03101891) and planned multicenter trial.

Survival and healthcare utilization of infants diagnosed with lethal congenital malformations

OBJECTIVE

We assessed survival, hospital length of stay (LOS), and costs of medical care for infants with lethal congenital malformations, and also examined the relationship between medical and surgical therapies and survival.

STUDY DESIGN

Retrospective cohort study including infants born 1998-2009 with lethal congenital malformations, identified using a longitudinally linked maternal/infant database.

RESULTS

The cohort included 786 infants: trisomy 18 (T18, n = 350), trisomy 13 (T13, n = 206), anencephaly (n = 125), bilateral renal agenesis (n = 53), thanatophoric dysplasia/achondrogenesis/lethal osteogenesis imperfecta (n = 38), and infants > 1 of the birth defects (n = 14). Compared to infants without birth defects, infants with T18, T13, bilateral renal agenesis, and skeletal dysplasias had longer survival rates, higher inpatient medical costs, and longer LOS.

CONCLUSION

Care practices and survival have changed over time for infants with T18, T13, bilateral renal agenesis, and skeletal dysplasias. This information will be useful for clinicians in counseling families and in shaping goals of care prenatally and postnatally.

Management of antenatally detected kidney malformations

Congenital anomalies of the kidneys and the urinary tract (CAKUT) are one of the most common sonographically identified antenatal malformations. Dilatation of the renal pelvis accounts for the majority of cases, but this is usually mild rather than an indicator of obstructive uropathy. Other conditions such as small through large hyperechogenic and/or cystic kidneys present a significant diagnostic dilemma on routine scanning. Accurate diagnosis and prediction of prognosis is often not possible without a positive family history, although maintenance of adequate amniotic fluid is usually a good sign. Both pre- and postnatal genetic screening is possible for multiple known CAKUT genes but less than a fifth of non-syndromic sporadic cases have detectable monogenic mutations with current technology. In utero management options are limited, with little evidence of benefit from shunting of obstructed systems or installation of artificial amniotic fluid. Often outcome hinges on associated cardiac, neurological or other abnormalities, particularly in syndromic cases. Hence, management centres on a careful assessment of all anomalies and planning for postnatal care. Early delivery is rarely indicated since this exposes the baby to the risks of prematurity in addition to their underlying CAKUT. Parents value discussions with a multidisciplinary team including fetal medicine and paediatric nephrology or urology, with neonatologists to plan perinatal care and clinical geneticists for future risks of CAKUT.

Ethical Considerations Concerning Amnioinfusions for Treating Fetal Bilateral Renal Agenesis

Congenital bilateral renal agenesis has been considered a uniformly fatal condition. However, the report of using serial amnioinfusions followed by the live birth in 2012 and ongoing survival of a child with bilateral renal agenesis has generated hope, but also considerable controversy over an array of complex clinical and ethical concerns. To assess the ethical concerns associated with using serial amnioinfusions for bilateral renal agenesis, we assembled a multidisciplinary group to map the ethical issues relevant to this novel intervention. The key ethical issues identified were related to 1) potential risks and benefits, 2) clinical care compared with innovation compared with research, 3) counseling of expectant parents, 4) consent, 5) outcome measures, 6) access and justice, 7) conflicts of interest, 8) effects on clinicians, 9) effects on institutions, and 10) long-term societal implications. These ethical issues should be addressed in conjunction with systematic efforts to examine whether this intervention is safe and effective. Future work should capture the experiences of expectant parents, women who undergo serial amnioinfusions, those born with bilateral renal agenesis and their families as well as clinicians confronted with making difficult choices related to it.

Lower urinary tract obstruction: fetal intervention based on prenatal staging

The authors present an overview of lower urinary tract obstruction (LUTO) in the fetus with a particular focus on the insult to the developing renal system. Diagnostic criteria along with the challenges in estimating long-term prognosis are reviewed. A proposed prenatal LUTO disease severity classification to guide management decisions with fetal intervention to maintain or salvage in utero and neonatal pulmonary and renal function is also discussed. Stage I LUTO (mild form) is characterized by normal amniotic fluid index after 18 weeks, normal kidney echogenicity, no renal cortical cysts, no evidence of renal dysplasia, and favorable urinary biochemistries when sampled between 18 and 30 weeks; prenatal surveillance is recommended. Stage II LUTO is characterized by oligohydramnios/anhydramnios, hyperechogenic kidneys but absent renal cortical cysts or apparent signs of renal dysplasia and favorable fetal urinary biochemistry; fetal vesicoamniotic shunting (VAS) or fetal cystoscopy is indicated to prevent pulmonary hypoplasia and renal failure. Stage III LUTO is oligohydramnios/anhydramnios, hyperechogenic kidneys with cortical cysts and renal dysplasia and unfavorable fetal urinary biochemistry after serial evaluation; fetal vesicoamniotic shunt may prevent severe pulmonary hypoplasia but not renal failure. Stage IV is characterized by intrauterine fetal renal failure, defined by anhydramnios and ultrasound (US) findings suggestive of severe renal dysplasia, and is associated with death in 24 h of life or end-stage renal disease (ESRD) within the first week of life; fetal vesicoamniotic shunt and fetal cystoscopy are not indicated.

Pediatric kidney transplantation

Since first performed in 1954, kidney transplantation has evolved as the preferred long-term treatment of children with end stage renal disease (ESRD). The etiology of chronic kidney disease (CKD) and ESRD in children is broad and can be quite complicated, necessitating a multidisciplinary team to adequately care for these patients and their myriad needs. Precise surgical techniques and modern protocols for immunosuppression provide excellent long-term patient and graft survival. This article reviews the many etiologies of renal failure in the pediatric population focusing on those most commonly leading to the need for kidney transplantation. The processes of evaluation, kidney transplantation, short-term and long-term complications, as well as long-term outcomes are also reviewed.

Evidence-based, ethically justified counseling for fetal bilateral renal agenesis

BACKGROUND

Not much data are available on the natural history of bilateral renal agenesis, as the medical community does not typically offer aggressive obstetric or neonatal care asbilateral renal agenesis has been accepted as a lethal condition.

AIM

To provide an evidence-based, ethically justified approach to counseling pregnant women about the obstetric management of bilateral renal agenesis.

STUDY DESIGN

A systematic literature search was performed using multiple databases. We deploy an ethical analysis of the results of the literature search on the basis of the professional responsibility model of obstetric ethics.

RESULTS

Eighteen articles met the inclusion criteria for review. With the exception of a single case study using serial amnioinfusion, there has been no other case of survival following dialysis and transplantation documented. Liveborn babies die during the neonatal period. Counseling pregnant women about management of pregnancies complicated by bilateral renal agenesis should be guided by beneficence-based judgment informed by evidence about outcomes.

CONCLUSIONS

Based on the ethical analysis of the results from this review, without experimental obstetric intervention, neonatal mortality rates will continue to be 100%. Serial amnioinfusion therefore should not be offered as treatment, but only as approved innovation or research.

[Congenital anomalies of poor prognosis. Genetics Consensus Committee]

INTRODUCTION

The Genetic Branch of the Chilean Society of Paediatrics, given the draft Law governing the decriminalisation of abortion on three grounds, focusing on the second ground, which considers the "embryo or foetus suffering from a congenital structural anomaly or a genetic disorder incompatible with life outside the womb", met to discuss the scientific evidence according to which congenital anomalies (CA) may be included in this draft law.

METHODOLOGY

Experts in clinical genetics focused on 10 CA, reviewed the literature evidence, and met to discuss it.

RESULTS

It was agreed not to use the term "incompatible with life outside the womb", as there are exceptions and longer survivals, and change to "congenital anomaly of poor prognosis (CAPP)". Ten CA were evaluated: serious defects of neural tube closure: anencephaly, iniencephaly and craniorachischisis, pulmonary hypoplasia, acardiac foetus, ectopia cordis, non-mosaic triploidy, "limb body wall" complex, "body stalk" anomaly, trisomy 13, trisomy 18, and bilateral renal agenesis. Findings on the prevalence, natural history, prenatal diagnostic methods, survival, and reported cases of prolonged survival were analysed. Post-natal survival, existence of treatments, and outcomes, as well as natural history without intervention, were taken into account in classifying a CA as a CAPP.

CONCLUSION

A CAPP would be: anencephaly, severe pulmonary hypoplasia, acardiac foetus, cervical ectopia cordis, non-mosaic triploidy, limb body wall complex, body stalk anomaly, non-mosaic trisomy 13, non-mosaic trisomy 18, and bilateral renal agenesis. For their diagnosis, it is required that all pregnant women have access to assessments by foetal anatomy ultrasound and occasionally MRI, and cytogenetic and molecular testing.

Types and Outcome of Fetal Urinary Anomalies in Low Resource Setting Countries: A Retrospective Study

BACKGROUND

Congenital anomalies of the kidney and urinary tract in the developing countries have a poor prognosis due to limited experience in antenatal and postnatal management.

PATIENTS AND METHODS

A 3-year retrospective study was carried out from January 2011 to December 2013. The following data were collected and analyzed: maternal age, gravidity, parity, gestational age at diagnosis, and ultrasonography findings. Final diagnosis after birth, the performed surgeries, follow-up data, as well as survival at one year were also analyzed.

RESULTS

The mean age of the included patients was 28 years (range 20-35 years). The mean parity was 1.7 (range 0-4). The mean gestational age at diagnosis was 26 weeks (range 15-36 weeks). Consanguinity was reported in 10 cases (24.4 %). There were 25 males and 16 females. Bilateral renal agenesis was the commonest type (19.5 %). The anomalies of kidneys and urinary tract in our cases were associated with other anomalies in 8 cases (19.5 %). Oligohydramnios was detected in bilateral renal agenesis and posterior urethral valve. Surgical interference during the first 6 months was performed in 6 cases; pyeloplasty for unilateral or bilateral hydronephrosis was performed in 5 cases; and excision of solitary renal cyst performed in one case. By the end of the first year, two of the three cases with chronic renal disease, who were under peritoneal dialysis, died, and three cases who had undergone pyeloplasty were lost to follow-up.

CONCLUSION

Among the 41 cases with antenatally diagnosed renal and urinary malformations; bilateral renal agenesis was the commonest anomaly (19.5 %). There were high rates of induction of abortion, IUFD, and neonatal deaths. The poor outcome may be due to lack of experience in performing invasive therapeutic fetal procedures.

Defining and predicting 'intrauterine fetal renal failure' in congenital lower urinary tract obstruction

BACKGROUND

The aim of this study was to identify predictors of 'intrauterine fetal renal failure' in fetuses with severe congenital lower urinary tract obstruction (LUTO).

METHODS

We undertook a retrospective study of 31 consecutive fetuses with a diagnosis of LUTO in a tertiary Fetal Center between April 2013 and April 2015. Predictors of 'intrauterine fetal renal failure' were evaluated in those infants with severe LUTO who had either a primary composite outcome measure of neonatal death in the first 24 h of life due to severe pulmonary hypoplasia or a need for renal replacement therapy within 7 days of life. The following variables were analyzed: fetal bladder re-expansion 48 h after vesicocentesis, fetal renal ultrasound characteristics, fetal urinary indices, and amniotic fluid volume.

RESULTS

Of the 31 fetuses included in the study, eight met the criteria for 'intrauterine fetal renal failure'. All of the latter had composite poor postnatal outcomes based on death within 24 h of life (n = 6) or need for dialysis within 1 week of life (n = 2). The percentage of fetal bladder refilling after vesicocentesis at time of initial evaluation was the only predictor of 'intrauterine fetal renal failure' (cut-off <27 %, area under the time-concentration curve 0.86, 95 % confidence interval 0.68-0.99; p = 0.009).

CONCLUSION

We propose the concept of 'intrauterine fetal renal failure' in fetuses with the most severe forms of LUTO. Fetal bladder refilling can be used to reliably predict 'intrauterine fetal renal failure', which is associated with severe pulmonary hypoplasia or the need for dialysis within a few days of life.

Severe antenatally diagnosed renal disorders: background, prognosis and practical approach

Nowadays most renal disorders, especially urinary tract malformations and renal cystic disease, are diagnosed antenatally. In cases of severe bilateral disease, intrauterine renal dysfunction may lead to renal oligohydramnios (ROH), resulting in pulmonary hypoplasia which affects perinatal mortality and morbidity as well as the long-term outcome. However, some infants may only have mild pulmonary and renal disease, and advances in postnatal and dialysis treatment have resulted in improved short- and long-term outcome even in those infants with severe ROH. Here, we review the current state of knowledge and clinical experience of patients presenting antenatally with severe bilateral renal disorders and ROH. By addressing underlying mechanisms, intrauterine tools of diagnosis and treatment as well as published outcome data, we hope to improve antenatal counselling and postnatal care. KEY SUMMARY POINTS: 1. Nowadays most renal disorders are diagnosed antenatally, especially urinary tract malformations and renal cystic disease. 2. Severe kidney dysfunction may lead to renal oligohydramnios, which can cause pulmonary hypoplasia and is a risk factor of perinatal mortality and postnatal renal outcome. However, as considerable clinical heterogeneity is present, outcome predictions need to be treated with caution. 3. Advances in postnatal and dialysis treatment have resulted in improved short- and long-term outcomes even in infants with severe renal oligohydramnios. 4. A multidisciplinary approach with specialist input is required when counselling a family with an ROH-affected fetus as the decision-making process is very challenging.

Fetal Lower Urinary Tract Obstruction (LUTO): a practical review for providers

Fetal lower urinary tract obstruction (LUTO) is a serious condition, which commonly results in marked perinatal morbidity and mortality. The characteristic prenatal presentation of LUTO includes an enlarged bladder with bilateral obstructive uropathy. While mild forms of the disease result in minimal clinical sequelae, the more severe forms commonly lead to oligohydramnios, dysplastic changes in the fetal kidneys, and ultimately result in secondary pulmonary hypoplasia. The aim of this review is to provide practitioners with a practical and concise overview of the presentation, evaluation, and treatment of LUTO.

Ethical language and decision-making for prenatally diagnosed lethal malformations

In clinical practice, and in the medical literature, severe congenital malformations such as trisomy 18, anencephaly, and renal agenesis are frequently referred to as 'lethal' or as 'incompatible with life'. However, there is no agreement about a definition of lethal malformations, nor which conditions should be included in this category. Review of outcomes for malformations commonly designated 'lethal' reveals that prolonged survival is possible, even if rare. This article analyses the concept of lethal malformations and compares it to the problematic concept of 'futility'. We recommend avoiding the term 'lethal' and suggest that counseling should focus on salient prognostic features instead. For conditions with a high chance of early death or profound impairment in survivors despite treatment, perinatal and neonatal palliative care would be ethical. However, active obstetric and neonatal management, if desired, may also sometimes be appropriate.