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

An Ethical Analysis of Therapy for Severe Congenital Kidney and Urinary Tract Anomalies

Technological advancements before and after delivery have greatly altered the counseling of pregnant patients facing a fetal diagnosis of severe oligohydramnios or anhydramnios secondary to congenital anomalies of the kidneys and urinary tract. Once considered a nearly uniformly lethal abnormality, long-term survival may now be possible secondary to prenatal innovations aimed at restoring the amniotic fluid volume and the availability of more advanced neonatal dialysis techniques. However, these available therapies are far from perfect. The procedures are onerous for pregnant patients without a guarantee of success, and families must prepare themselves for the complex life-long medical care that will be necessary for surviving individuals. Multidisciplinary counseling is imperative to help pregnant individuals understand the complexity of these conditions and assist them in exercising their right to informed decision-making. Moreover, as with any developing field of medicine, providers must contend with ethical questions related to the treatment options, including questions regarding patient-hood, distributive justice, and the blurred lines between research, innovation, and standard care. These ethical questions are best addressed in a multidisciplinary fashion with consideration of multiple points of view from various subspecialties. Only by seeing the entirety of the picture can we hope to best counsel patients about these highly complex situations and help navigate the most appropriate care path.

Single-center Incidence and Patterns of Stroke in Early Renal Anhydramnios after Serial Amnioinfusions

The Renal Anhydramnios Fetal Therapy (RAFT) trial is a study of serial amnioinfusions to prevent lethal neonatal pulmonary hypoplasia from early renal anhydramnios. Infant neurologic outcomes were not originally evaluated. We describe the high incidence of stroke observed among infants in the treatment arm of the trial at our center.

Prenatally-diagnosed renal failure: an ethical framework for decision-making

The Children's Hospital Working Group has developed an ethical framework to guide patient care and research for prenatally diagnosed severe renal anomalies. It identifies ethical challenges in communication, timing of decisions and scarce resources. Key elements include shared decision-making, establishing a trusting relationship, and managing disagreement. The ethical framework will be used to develop a clinical pathway that operationalizes the key values of trust, honesty, transparency, beneficence, nonmaleficence, respecting parental authority, professional integrity, and justice.

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.

The genetic etiologies of bilateral renal agenesis

OBJECTIVE

The goal of this study was to review and analyze the medical literature for cases of prenatal and/or postnatally diagnosed bilateral renal agenesis (BRA) and create a comprehensive summary of the genetic etiologies known to be associated with this condition.

METHODS

A literature search was conducted as a scoping review employing Online Mendeliain Inheritance in Man, PubMed, and Cochrane to identify cases of BRA with known underlying genetic (chromosomal vs. single gene) etiologies and those described in syndromes without any known genetic etiology. The cases were further categorized as isolated versus non-isolated, describing additional findings reported prenatally, postnatally, and postmortem. Inheritance pattern was also documented when appropriate in addition to the reported timing of diagnosis and sex.

RESULTS

We identified six cytogenetic abnormalities and 21 genes responsible for 20 single gene disorders associated with BRA. Five genes have been reported to associate with BRA without other renal anomalies; sixteen others associate with both BRA as well as unilateral renal agenesis. Six clinically recognized syndromes/associations were identified with an unknown underlying genetic etiology. Genetic etiologies of BRA are often phenotypically expressed as other urogenital anomalies as well as complex multi-system syndromes.

CONCLUSION

Multiple genetic etiologies of BRA have been described, including cytogenetic abnormalities and monogenic syndromes. The current era of the utilization of exome and genome-wide sequencing is likely to significantly expand our understanding of the underlying genetic architecture of BRA.

MAGED2 Depletion Promotes Stress-Induced Autophagy by Impairing the cAMP/PKA Pathway

Melanoma-associated antigen D2 (MAGED2) plays an essential role in activating the cAMP/PKA pathway under hypoxic conditions, which is crucial for stimulating renal salt reabsorption and thus explaining the transient variant of Bartter's syndrome. The cAMP/PKA pathway is also known to regulate autophagy, a lysosomal degradation process induced by cellular stress. Previous studies showed that two members of the melanoma-associated antigens MAGE-family inhibit autophagy. To explore the potential role of MAGED2 in stress-induced autophagy, specific MAGED2-siRNA were used in HEK293 cells under physical hypoxia and oxidative stress (cobalt chloride, hypoxia mimetic). Depletion of MAGED2 resulted in reduced p62 levels and upregulation of both the autophagy-related genes (ATG5 and ATG12) as well as the autophagosome marker LC3II compared to control siRNA. The increase in the autophagy markers in MAGED2-depleted cells was further confirmed by leupeptin-based assay which concurred with the highest LC3II accumulation. Likewise, under hypoxia, immunofluorescence in HEK293, HeLa and U2OS cell lines demonstrated a pronounced accumulation of LC3B puncta upon MAGED2 depletion. Moreover, LC3B puncta were absent in human fetal control kidneys but markedly expressed in a fetal kidney from a MAGED2-deficient subject. Induction of autophagy with both physical hypoxia and oxidative stress suggests a potentially general role of MAGED2 under stress conditions. Various other cellular stressors (brefeldin A, tunicamycin, 2-deoxy-D-glucose, and camptothecin) were analyzed, which all induced autophagy in the absence of MAGED2. Forskolin (FSK) inhibited, whereas GNAS Knockdown induced autophagy under hypoxia. In contrast to other MAGE proteins, MAGED2 has an inhibitory role on autophagy only under stress conditions. Hence, a prominent role of MAGED2 in the regulation of autophagy under stress conditions is evident, which may also contribute to impaired fetal renal salt reabsorption by promoting autophagy of salt-transporters in patients with MAGED2 mutation.

Prenatal Diagnoses and Intervention

Fetal upper tract urinary system dilation is one of the most common findings on prenatal ultrasonography. Rarely, this may represent fetal lower urinary tract obstruction (LUTO), of which posterior urethral valves are the predominant etiology. LUTO is the most dire fetal urologic diagnosis, as it affects not only the baby's management after birth but sometimes the course of the pregnancy itself. A variety of treatment options are available prenatally; these include observation, vesicoamniotic shunt placement, amnioinfusion, and attempts at direct treatment of the valves themselves. All fetal interventions carry substantial risks; caution should attend every discussion of treatment.

Lower Urinary Tract Obstruction in Newborns

Lower urinary tract obstruction (LUTO) is a rare birth defect with a prevalence between 1 in 5,000 and 1 in 25,000 pregnancies. LUTO is one of the most common causes of congenital abnormalities of the renal tract. Several genetic conditions have been associated with LUTO. Most common causes of LUTO are posterior urethral valves and urethral atresia. Despite available prenatal and postnatal treatments, LUTO is a significant cause of morbidity and mortality in newborns causing significant end stage renal disease and pulmonary hypoplasia.

Lifesaving Treatments for the Tiniest Patients-A Narrative Description of Old and New Minimally Invasive Approaches in the Arena of Fetal Surgery

Fetal surgery has become a lifesaving reality for hundreds of fetuses each year. The development of a formidable spectrum of safe and effective minimally invasive techniques for fetal interventions since the early 1990s until today has led to an increasing acceptance of novel procedures by both patients and health care providers. From his vast personal experience of more than 20 years as one of the pioneers at the forefront of clinical minimally invasive fetal surgery, the author describes and comments on old and new minimally invasive approaches, highlighting their lifesaving or quality-of-life-improving potential. He provides easy-to-use practical information on how to perform partial amniotic carbon dioxide insufflation (PACI), how to assess lung function in fetuses with pulmonary hypoplasia, how to deal with giant CPAMS, how to insert shunts into fetuses with LUTO and hydrothorax when conventional devices are not available, and how to resuscitate a fetus during fetal cardiac intervention. Furthermore, the author proposes a curriculum for future fetal surgeons, solicits for the centralization of patients, for adequate maternal counseling, for adequate pain management and adequate hygienic conditions during interventions, and last but not least for starting the process of academic recognition of the matured field as an independent specialty. These steps will allow more affected expectant women and their unborn children to gain access to modern minimally invasive fetal surgery and therapy. The opportunity to treat more patients at dedicated centers will also result in more opportunities for the research of rare diseases and conditions, promising even better pre- and postnatal care in the future.

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.

Expanding neonatal ECMO criteria: When is the premature neonate too premature

Extracorporeal membrane oxygenation (ECMO) is a universally accepted and life-saving therapy for neonates with respiratory or cardiac failure that is refractory to maximal medical management. Early studies found unacceptable risks of mortality and morbidities such as intracranial hemorrhage among premature and low birthweight neonates, leading to widely accepted ECMO inclusion criteria of gestational age ≥34 weeks and birthweight >2 kg. Although contemporary data is lacking, the most recent literature demonstrates increased survival and decreased rates of intracranial hemorrhage in premature neonates who are supported with ECMO. As such, it seems like the right time to push the boundaries of ECMO on a case-by-case basis beginning with neonates 32-34 weeks GA in large volume centers with careful neurodevelopmental follow-up to better inform practices changes on this select population.

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.

Management Practices During Perinatal Respiratory Transition of Very Premature Infants

The present review considers some controversial management practices during extremely premature perinatal transition. We focus on perinatal prevention and treatment of respiratory distress syndrome (RDS) in immature infants. New concerns regarding antenatal corticosteroid management have been raised. Many fetuses are only exposed to potential adverse effects of the drug. Hence, the formulation and the dosage may need to be modified. Another challenge is to increase the fraction of the high-risk fetuses that benefit from the drug and to minimize the harmful effects of the drug. On the other hand, boosting anti-inflammatory and anti-microbial properties of surfactant requires further attention. Techniques of prophylactic surfactant administration to extremely immature infants at birth may be further refined. Also, new findings suggest that prophylactic treatment of patent ductus arteriosus (PDA) of a high-risk population rather than later selective closure of PDA may be preferred. The TREOCAPA trial (Prophylactic treatment of the ductus arteriosus in preterm infants by acetaminophen) evaluates, whether early intravenous paracetamol decreases the serious cardiorespiratory consequences following extremely premature birth. Lastly, is inhaled nitric oxide (iNO) used in excess? According to current evidence, iNO treatment of uncomplicated RDS is not indicated. Considerably less than 10% of all very premature infants are affected by early persistence of pulmonary hypertension (PPHN). According to observational studies, effective ventilation combined with early iNO treatment are effective in management of this previously fatal disease. PPHN is associated with prolonged rupture of fetal membranes and birth asphyxia. The lipopolysaccharide (LPS)-induced immunotolerance and hypoxia-reperfusion-induced oxidant stress may inactivate NO-synthetases in pulmonary arterioles and terminal airways. Prospective trials on iNO in the management of PPHN are indicated. Other pulmonary vasodilators may be considered as comparison drugs or adjunctive drugs. The multidisciplinary challenge is to understand the regulation of pregnancy duration and the factors participating the onset of extremely premature preterm deliveries and respiratory adaptation. Basic research aims to identify deficiencies in maternal and fetal tissues that predispose to very preterm births and deteriorate the respiratory adaptation of immature infants. Better understanding on causes and prevention of extremely preterm births would eventually provide effective antenatal and neonatal management practices required for the intact survival.

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.

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.

Evaluation and fetal intervention in severe fetal hydronephrosis

PURPOSE OF REVIEW

Fetal hydronephrosis secondary to congenital anomalies of the kidney and urinary tract (CAKUT) can adversely affect neonates in the postnatal period with long-term consequences. A prenatal diagnosis of CAKUT can have an early fetal intervention to minimize these consequences. This review aims to provide an overview of the possible fetal intervention with severe hydronephrosis.

RECENT FINDINGS

Clinical course and outcomes of CAKUT are predicted based on biochemical markers and radiological findings. In spite of advancements and accurately diagnosing the severity of hydronephrosis, there are many controversies surround on selection of cases with antenatal hydronephrosis (ANH) that will benefit from fetal intervention. Despite better diagnosis and techniques fetal intervention is limited to mainly lower urinary tract obstruction patients to improve amniotic fluid volume and assist in lung development.

SUMMARY

ANH can potentially detect the severity of congenital renal anomalies but unable to recognize a specific disease. A multidisciplinary approach is required to diagnose and properly stage cases of severe CAKUT and potential surgical intervention can be considered.

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.

Fetal lower urinary tract obstruction: What should we tell the prospective parents?

Fetal lower urinary tract obstruction (LUTO), which often results in marked perinatal morbidity and mortality, is caused by a heterogeneous group of anatomical defects that lead to blockage of the urethra. The classic prenatal presentation of LUTO includes megacystis with hydronephrosis. While mild forms of the disease can be associated with favorable outcomes, more severe disease commonly leads to dysplastic changes in the fetal kidneys, and ultimately oligohydramnios, which can result in secondary pulmonary hypoplasia and renal failure at birth. The aim of this review is to provide practitioners with a general overview of the diagnosis and treatment of LUTO based on disease severity, along with some points to consider when counseling prospective parents of fetuses with this condition.

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.