Bendel‐Stenzel, Ellen

Importance Anhydramnios from fetal kidney failure causes lethal pulmonary hypoplasia. Serial amnioinfusions have shown promise in mitigating pulmonary disease from bilateral renal agenesis, but efficacy and safety for other causes of fetal kidney failure are unproven. Objective To assess the efficacy of serial amnioinfusions initiated before 26 weeks’ gestation to mitigate lethal pulmonary hypoplasia in cases of anhydramnios due to fetal kidney failure. Design, Setting, and Participants Prospective, nonrandomized clinical trial conducted at 13 US fetal therapy centers from December 2018 to February 2025. Outcomes for maternal-fetal pairs with anhydramnios before 22 weeks’ gestation due to fetal kidney failure without bilateral renal agenesis are reported; data collection for surviving infants continued until February 13, 2026. Exposure Thirty-two participants underwent serial amnioinfusions with isotonic fluid beginning before 26 weeks’ gestation. Main Outcomes and Measures The primary end point was neonatal survival for 14 days or longer with dialysis access placement. Secondary outcome measures of survival to discharge home and kidney transplant are reported. Results Twenty-nine of 32 participants (91%) had a live birth, with a median (IQR) gestational age at delivery of 34 weeks 1 day (31 weeks 5 days to 34 weeks 6 days). All participants delivered before 37 weeks’ gestation. No unexpected serious maternal adverse events occurred, and the most common maternal complications were preterm prelabor rupture of membranes in 19 participants (56%) and chorioamniotic separation in 10 (29%). The primary outcome occurred in 19 (65.5%) of 29 live-born neonates (95% CI, 45.7%-82.1%). Factors associated with survival to the primary outcome included receiving more amnioinfusions (median [IQR], 14 [9-18] in survivors vs 7 [4-11] in nonsurvivors; P = .01), longer time interval from first amnioinfusion to preterm prelabor rupture of membranes (63.5 [60.5-74.5] days in survivors vs 29.0 [22.0-56.0] days in nonsurvivors; P = .01), gestational age greater than 32 weeks (79% of survivors vs 38% of nonsurvivors; P = .03), and higher birth weight (2029 [1770-2250] g in survivors vs 1635 [1185-1915] g in nonsurvivors; P = .01). Fourteen live-born infants (48%) survived to hospital discharge at a median (IQR) age of 4.7 (3.4-5.7) months. Of the 11 infants surviving to date, 7 (64%) have undergone kidney transplant between ages 2 years to 5 years. Conclusions and Relevance Serial amnioinfusions mitigated lethal pulmonary hypoplasia in neonates with anhydramnios due to fetal kidney failure. Significant neonatal morbidity and mortality independent of early lung function was noted. Factors associated with survival were consistent with the Renal Anhydramnios Fetal Therapy trial’s bilateral renal agenesis cohort, suggesting common mechanistic pathways for mitigating pulmonary hypoplasia. Trial Registration ClinicalTrials.gov Identifier: NCT03101891

BACKGROUND & OBJECTIVE Sleep-disordered breathing (SDB) may be a remediable contributor to abnormal cognitive outcomes for children with myelomeningocele. We investigated the frequency of SDB among neonates with fetal vs postnatal myelomeningocele repair. METHODS In this nine-center, prospective, observational study, neonates with myelomeningocele born at more than 30 weeks gestational age underwent a 10-hour bedside polysomnogram at at least 35 weeks postmenstrual age, before hospital discharge. The primary outcome was SDB severity, reflected by the apnea-hypopnea index (AHI; number of respiratory events per hour of sleep). Decisions regarding surgical timing (fetal vs postnatal), technique (open fetal vs fetoscopic approach), and SDB treatment were made by the clinical teams. RESULTS Among 173 infants, 92/173 (53%) had SDB (median AHI 22.5, IQR 12.2–44.2). In unadjusted analysis, AHI was higher among the 90 neonates with fetal repair vs 83 with postnatal surgery (median 29, IQR 14–49, vs 19, IQR 10–36, P = .008). In propensity-adjusted multivariable models, prematurity was independently associated with AHI, whereas surgical timing (fetal vs postnatal) was not. Hindbrain herniation, myelomeningocele level, and clinical need for ventriculoperitoneal shunt did not predict AHI in adjusted models. Supplemental oxygen was commonly prescribed, for 44% of fetal vs 39% of postnatal myelomeningocele repair infants (P = .5). CONCLUSIONS SDB affects more than half of neonates with myelomeningocele. The higher AHI after fetal surgery could stem from the elevated incidence of prematurity in this group. As SDB is treatable and has a potential impact on neurodevelopment, routine screening could become an integral part of a strategy to optimize long-term medical and neurodevelopmental outcomes.

Objective This study aimed to determine the prevalence and heteroplasmy level(s) of MT-RNR1 variants m.1555A > G and m.1494C > T, which are associated with aminoglycoside-induced hearing loss, in a general perinatal population. This study also aimed to characterize the association of these variants and their heteroplasmy levels with hearing loss outcomes with and without aminoglycoside exposure. Study Design Droplet digital polymerase chain reaction was performed on 479 maternal DNA samples from a general perinatal biobank at our institution to detect the presence and heteroplasmy levels of MT-RNR1 variants m.1555A > G and m.1494C > T. Testing of paired neonatal specimen(s) was planned for positive maternal tests. A retrospective chart review was performed to characterize the population, identify aminoglycoside exposures, and determine hearing outcomes. Results All maternal samples tested negative for MT-RNR1 variants m.1555A > G and m.1494C > T. Maternal and neonatal subjects had high rates of aminoglycoside exposure (15.9 and 13.9%, respectively). No subjects with sensorineural or mixed hearing loss had documented aminoglycoside exposure. Conclusion This study demonstrated that a larger sample size is needed to establish the prevalence of these variants as no subjects tested positive. Determination of variant prevalence in the neonatal population, association of variant heteroplasmy levels with hearing outcomes, and reliability of maternal testing as a surrogate for neonatal testing are important next steps toward universal prenatal or newborn screening. Key Points

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.

ImportanceEarly 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.ObjectiveTo assess neonatal outcomes of serial amnioinfusions initiated before 26 weeks’ gestation to mitigate lethal pulmonary hypoplasia.Design, Setting, and ParticipantsProspective, 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.ExposureEnrolled 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 MeasuresThe primary end point was postnatal infant survival to 14 days of life or longer with dialysis access placement.ResultsThe 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 RelevanceSerial 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 RegistrationClinicalTrials.gov Identifier: NCT03101891

There is a broad phenotypic spectrum of monogenic polycystic kidney diseases (PKDs). These disorders often involve cilia-related genes and lead to the development of fluid-filled cysts and eventual kidney function decline and failure. Preimplantation genetic testing for monogenic (PGT-M) disorders has moved into the clinical realm. It allows prospective parents to avoid passing on heritable diseases to their children, including monogenic PKD. The PGT-M process involves embryo generation through in vitro fertilization, with subsequent testing of embryos and selective transfer of those that do not harbor the specific disease-causing variant(s). There is a growing body of literature supporting the success of PGT-M for autosomal-dominant and autosomal-recessive PKD, although with important technical limitations in some cases. This technology can be applied to many other types of monogenic PKD and ciliopathies despite the lack of existing reports in the literature. PGT-M for monogenic PKD, like other forms of assisted reproductive technology, raises important ethical questions. When considering PGT-M for kidney diseases, as well as the potential to avoid disease in future generations, there are regulatory and ethical considerations. These include limited government regulation and unstandardized consent processes, potential technical errors, high cost and equity concerns, risks associated with pregnancy for mothers with kidney disease, and the impact on all involved in the process, including the children who were made possible with this technology.

Objective The effect of gestational age (GA) on gastroschisis outcomes is unclear and delivery timing varies in practice. We aimed to correlate clinical outcomes of infants with gastroschisis and GA at delivery in the Children's Hospitals Neonatal Consortium (CHNC). Study Design This was a retrospective multicenter cohort study of infants with gastroschisis admitted to CHNC neonatal intensive care units (NICUs) from 2010 to 2016. Patients were categorized by GA: 32 to 346/7, 35 to 366/7, and ≥37 weeks. Respiratory and feeding interventions, mortality, length of stay, and common complications were compared. Results In 2021 for patients with gastroschisis, median GA at delivery was 36.3 weeks (interquartile range [IQR] 35.1, 37.3) and mean birth weight 2,425 g (IQR 2,100, 2,766). Overall mortality was low and there was no difference across GA groups. Infants <35 weeks' gestation had the greatest need for respiratory and feeding interventions. Complications such as medical necrotizing enterocolitis (NEC), cholestasis, and central line-associated blood stream infection were less common in infants ≥37 weeks. Feeding initiation and full feeds were earliest in term infants, compared with infants between 35 and 366/7 weeks, and longest in infants <35 weeks. Prematurity had a significant negative association with breast milk exposure. Enteral feeding tube support at discharge increased with prematurity. Compared with term, infants born between 35 and 366/7 weeks' gestation had a higher incidence of medical NEC and lower exposure to mother's milk at discharge but the need for respiratory interventions or tube feeding at discharge was similar. Conclusion Premature infants with gastroschisis had more neonatal complications including respiratory interventions, longer NICU stay, longer time to full enteral feeds, and higher need for tube feeds at discharge as compared with those delivered at term. Differences were greatest for those <35 weeks GA. While overall mortality remains low, these results provide additional information about GA at birth in gastroschisis, with no evidence of benefit from preterm delivery. Key Points

Fetal kidney development is a complex and carefully orchestrated process. The proper formation of kidney tissue involves many transcription factors and signaling pathways. Pathogenic variants in the genes that encodethese factors and proteins can result in neonatal cystic kidney disease. Advancements in genomic sequencing have allowed us to identify many of these variants and better understand the genetic underpinnings for an increasing number of presentations of childhood kidney disorders. This review discusses the genes essential in kidney development, particularly those involved in the structure and function of primary cilia, and implications of gene identification for prognostication and management of cystic kidney disorders.