North American Fetal Therapy Network: Maternal Outcomes in Fetal Aqueductal Stenosis.

INTRODUCTION: Fetal aqueductal stenosis (AS) affects approximately 1:1,000 pregnancies. Obstruction of cerebral spinal fluid (CSF) circulation occurs at the aqueduct of Sylvius, leading to progressive hydrocephalus, often necessitating cesarean section (CS) with a classical uterine incision. The purpose of this study is to describe maternal outcomes associated with fetal aqueductal stenosis. METHODS: This study is conducted through the North American Fetal Therapy Network (NAFTNet). Subjects were recruited at the diagnosis of severe CNS ventriculomegaly and were followed longitudinally. Maternal events around the delivery of fetuses with AS were recorded and analyzed. RESULTS: Thirty-seven subjects with fetal AS confirmed by neonatal neuroimaging were analyzed. The average gestation at delivery was 36.7 weeks. Overall, 86% were delivered by cesarean section (CS), and 62% of these were elective. Sixty-two percent were delivered electively by cesarean section (CS). Eighty-six percent were delivered by cesarean section. Ninety one percent of CSs were performed through a Pfannenstiel abdominal incision. A classical uterine incision was required in 13% of cesarean deliveries. The peripartum complication rate was 27%. CONCLUSION: Women carrying a fetus with AS were at risk for preterm birth, cesarean delivery, a classical uterine incision, and peripartum complications. These data highlight the maternal morbidity associated with fetal AS, and the potential benefit of in-utero therapy not only for neonatal but also maternal outcomes.

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.

Society for Maternal-Fetal Medicine Consult Series #72: Twin-twin transfusion syndrome and twin anemia-polycythemia sequence.

30% of spontaneously occurring twins are monozygotic, of which two-thirds are monochorionic, possessing a single placenta. A common placental mass with shared inter-twin placental circulation is key to the development and management of complications unique to monochorionic gestations. In this Consult, we review general considerations and a contemporary approach to twin-twin transfusion syndrome and twin anemia polycythemia sequence, providing management recommendations based on the available evidence. The following are Society for Maternal-Fetal Medicine recommendations: (1) we recommend routine first trimester sonographic determination of chorionicity and amnionicity (GRADE 1B); (2) we recommend that ultrasound surveillance for twin-twin transfusion syndrome begin at 16 weeks of gestation for all monochorionic-diamniotic twin pregnancies and continue at least every 2 weeks until delivery, with more frequent monitoring indicated with clinical concern (GRADE 1C); (3) we recommend that routine sonographic surveillance for twin-twin transfusion syndrome minimally include assessment of amniotic fluid volumes on both sides of the inter-twin membrane and evaluation for the presence or absence of urine-filled fetal bladders, and ideally incorporate Doppler study of the umbilical arteries (GRADE 1C); (4) we recommend fetoscopic laser surgery as the standard treatment for stage II through stage IV twin-twin transfusion syndrome presenting between 16 and 26 weeks of gestation (GRADE 1A); (5) we recommend expectant management with at least weekly fetal surveillance for asymptomatic patients continuing pregnancies complicated by stage I twin-twin transfusion syndrome, and consideration for fetoscopic laser surgery for stage I twin-twin transfusion syndrome presentations between 16 and 26 weeks of gestation complicated by additional factors such as maternal polyhydramnios-associated symptomatology (GRADE 1B); (6) we recommend an individualized approach to laser surgery for early- and late-presenting twin-twin transfusion syndrome (GRADE 1C); (7) we recommend that all patients with twin-twin transfusion syndrome qualifying for laser therapy be referred to a fetal intervention center for further evaluation, consultation, and care (Best Practice); (8) after laser therapy, we suggest weekly surveillance for 6 weeks followed by resumption of every-other-week surveillance thereafter, unless concern exists for post-laser twin-twin transfusion syndrome, post-laser twin anemia polycythemia sequence, or fetal growth restriction (GRADE 2C); (9) following the resolution of twin-twin transfusion syndrome after fetoscopic laser surgery, and without other indications for earlier delivery, we recommend delivery of dual-surviving monochorionic-diamniotic twins at 34 to 36 weeks of gestation (GRADE 1C); (10) in twin-twin transfusion syndrome pregnancies complicated by post-treatment single fetal demise, we recommend full-term delivery (39 weeks) of the surviving co-twin to avoid complications of prematurity unless indications for earlier delivery exist (GRADE 1C); (11) we recommend that fetoscopic laser surgery should not influence the mode of delivery (Best Practice); (12) we recommend that prenatal diagnosis of twin anemia polycythemia sequence minimally requires either middle cerebral artery Doppler peak systolic velocity values >1.5 multiples of the median and <1.0 multiples of the median in donor and recipient twins, respectively, or an inter-twin Δ middle cerebral artery peak systolic velocity >0.5 multiples of the median (GRADE 1C); (13) we recommend that providers consider incorporating middle cerebral artery Doppler peak systolic velocity determinations into all monochorionic twin ultrasound surveillance beginning at 16 weeks of gestation (GRADE 1C); (14) consultation with a specialized fetal care center is recommended when twin anemia polycythemia sequence progresses to a more advanced disease stage (≥ stage II) prior to 32 weeks of gestation or when concern arises for co-existing complications such as twin-twin transfusion syndrome (Best Practice).

Comparison of Serial Amnioinfusion Strategies for Isolated Early-Onset Fetal Renal Anhydramnios.

INTRODUCTION: The optimal protocol for serial amnioinfusions to maintain amniotic fluid in pregnancies with early-onset fetal renal anhydramnios before 22 weeks is not known. We compared the performance of two different approaches. METHODS: A secondary analysis was conducted of serial amnioinfusions performed by a single center during the external pilot and feasibility phases of the Renal Anhydramnios Fetal Therapy (RAFT) trial. During the external pilot, higher amnioinfusion volumes were given less frequently; in the feasibility study, smaller volume amnioinfusions were administered more frequently. Procedural details, complications, and obstetric outcomes were compared between the two groups using Pearson's χ2 or Fisher's exact tests for categorical variables and Student's t tests or Wilcoxon rank-sum tests for continuous variables. The adjusted association between procedural details and chorioamniotic separation was obtained through a multivariate repeated measure logistic regression model. RESULTS: Eleven participants underwent 159 amnioinfusions (external pilot: 3 patients, 21 amnioinfusions; feasibility: 8 patients, 138 amnioinfusions). External pilot participants had fewer amnioinfusions (7 vs. 19.5 in the feasibility group, p = 0.04), larger amnioinfusion volume (750 vs. 500 mL, p < 0.01), and longer interval between amnioinfusions (6 [4-7] vs. 4 [3-5] days, p < 0.01). In the external pilot, chorioamniotic separation was more common (28.6% vs. 5.8%, p < 0.01), preterm prelabor rupture of membranes (PPROM) occurred sooner after amnioinfusion initiation (28 ± 21.5 vs. 75.6 ± 24.1 days, p = 0.03), and duration of maintained amniotic fluid between first and last amnioinfusion was shorter (38 ± 17.3 vs. 71 ± 19 days, p = 0.03), compared to the feasibility group. While delivery gestational age was similar (35.1 ± 1.7 vs. 33.8 ± 1.5 weeks, p = 0.21), feasibility participants maintained amniotic fluid longer. CONCLUSION: Small volume serial amnioinfusions performed more frequently maintain normal amniotic fluid volume longer because of delayed occurrence of PPROM.

Management advances for congenital diaphragmatic hernia: integrating prenatal and postnatal perspectives.

In congenital diaphragmatic hernia (CDH), abdominal organs are displaced into the chest, compress the lungs, and cause mediastinal shift. This contributes to development of pulmonary hypoplasia and hypertension, which is the primary determinant of morbidity and mortality for affected newborns. The severity is determined using prenatal imaging as early as the first trimester and is related to the laterality of the defect, extent of lung compression, and degree of liver herniation. Comprehensive evaluation of fetal CDH includes imaging-based severity assessment, severity assessment, and evaluation for structural or genetic abnormalities to differentiate isolated from complex cases. Prenatal management involves multispecialty counseling, consideration for fetal therapy with fetoscopic endoluminal tracheal occlusion (FETO) for severe cases, monitoring and intervention for associated polyhydramnios or signs of preterm labor if indicated, administration of antenatal corticosteroids in the appropriate setting, and planned delivery to optimize the fetal condition at birth. Integrated programs that provide a smooth transition from prenatal to postnatal care produce better outcomes. Neonatal care involves gentle ventilation to avoid hyperinflation and must account for transitional physiology to avoid exacerbating cardiac dysfunction and decompensation. Infants who have undergone and responded to FETO have greater pulmonary capacity than expected, but cardiac dysfunction seems unaffected. In about 25-30% of CDH neonates extracorporeal life support is utilized, and this provides a survival benefit for patients with the highest predicted mortality, including those who underwent FETO. Surgical repair after initial medical management for the first 24-48 hours of life is preferred since later repair is associated with delayed oral feeding, increased need for tube feeds, and increased post-repair ventilation requirement and supplemental oxygen at discharge. With overall survival rates >70%, contemporary care involves management of chronic morbidities in the context of a multidisciplinary clinic setting.

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.

The role of fetal therapy in the management of mirror syndrome: a narrative review.

OBJECTIVES: Mirror syndrome (MS) is a condition characterized by the presence of maternal, fetal, and placental edema and is reversible through delivery or pregnancy termination. As fetal hydrops itself may be amenable to treatment, we sought to determine outcomes for MS primarily managed by fetal therapy through a narrative review of the literature and cases managed at our fetal center. STUDY DESIGN: PubMed, Embase, Web of Science, Scopus, and Google Scholar databases were searched through January 2024 using key words: mirror syndrome, Ballantyne's syndrome, fetal hydrops, maternal hydrops, pseudotoxemia, triple edema, maternal recovery, fetal therapy, and resolution. Manuscripts describing primary management by fetal therapy that included maternal and fetal outcomes were identified. Clinical details of MS patients managed with fetal therapy at our center were also included for descriptive analysis. RESULTS: 16 of 517 manuscripts (3.1%) described fetal therapy as the primary intended treatment in 17 patients. 3 patients managed at our center were included in the analysis. Among 20 patients undergoing primary fetal therapy for management of mirror syndrome, median gestational age of presentation was 24 weeks and 5 days gestation; predominant clinical findings were maternal edema (15/20), proteinuria (10/20), pulmonary edema (8/20), and hypertension (8/20); the primary laboratory abnormalities were anemia (8/20) and elevated creatinine or transaminases (5/20). Condition-specific fetal therapies led to resolution of hydrops in 17 (85%) cases and MS in 19 (95%) cases. The median time to hydrops resolution was 7.5 days and to resolution of mirror syndrome was 10 days. Fetal therapy prolonged pregnancy by a median of 10 weeks with a median gestational age of 35 weeks and 5 days at delivery. All women delivered for indications other than mirror syndrome and 19/20 fetuses survived. CONCLUSION: In appropriately selected cases, MS often resolves after fetal therapy of hydrops allowing for safe pregnancy prolongation with good maternal and infant outcomes.

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.

The utility of gene sequencing in identifying an underlying genetic disorder in prenatally suspected lower urinary tract obstruction.

OBJECTIVE: Fetal megacystis generally presents as suspected lower urinary tract obstruction (LUTO), which is associated with severe perinatal morbidity. Genetic etiologies underlying LUTO or a LUTO-like initial presentation are poorly understood. Our objectives are to describe single gene etiologies in fetuses initially ascertained to have suspected LUTO and to elucidate genotype-phenotype correlations. METHODS: A retrospective case series of suspected fetal LUTO positive for a molecular diagnosis was collected from five centers in the Fetal Sequencing Consortium. Demographics, sonograms, genetic testing including variant classification, and delivery outcomes were abstracted. RESULTS: Seven cases of initially prenatally suspected LUTO-positive for a molecular diagnosis were identified. In no case was the final diagnosis established as urethral obstruction that is, LUTO. All variants were classified as likely pathogenic or pathogenic. Smooth muscle deficiencies involving the bladder wall and interfering with bladder emptying were identified in five cases: MYOCD (2), ACTG2 (2), and MYH11 (1). Other genitourinary and/or non-genitourinary malformations were seen in two cases involving KMT2D (1) and BBS10 (1). CONCLUSION: Our series illustrates the value of molecular diagnostics in the workup of fetuses who present with prenatally suspected LUTO but who may have a non-LUTO explanation for their prenatal ultrasound findings.

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.

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.

How do we perform intrauterine transfusions?

BACKGROUND: Intrauterine transfusion (IUT) is an invasive but critical and potentially life-saving intervention for severe fetal anemia with demonstrated improvement in outcomes. The fetus is vulnerable to hemodynamic alterations and transfusion-related adverse events; therefore, special consideration must be given to blood component selection and modification. There is widespread IUT practice variability, and existing guidance primarily relies on expert opinion and single center experiences. STUDY DESIGN AND METHODS: Experts in Maternal Fetal Medicine, Pediatric Hematology, and Transfusion Medicine from centers across the United States, collectively performing about 120 IUT annually, offer a multidisciplinary perspective on the performance of IUT and preparation of blood components. This perspective includes strategies for identifying an at-risk fetus, communicating between disciplines, determining the necessary blood volume, selecting and processing blood components, documenting the procedure in medical record, and managing the neonate. RESULTS: Identifying an at-risk fetus relies on review of the clinical history, non-invasive monitoring, and laboratory evaluation. We recommend the use of relatively fresh, group O, cytomegalovirus-safe, freshly irradiated, red blood cells (RBC) that are Hemoglobin S negative and antigen-negative for any maternal antibody, if indicated. These RBC units should be concentrated to remove additives and increase the hematocrit thus minimizing fluctuations in fetal volume status. The units intended for IUT should be labeled clearly and the documentation of transfusion differentiated in the maternal medical record. DISCUSSION: An awareness of the technical, logistical, and regulatory considerations for IUT performance will facilitate improved communication and patient care, especially when rare units of RBC are required.

Serial lung mass volume ratios as prognostic indicators of neonatal respiratory morbidity in fetal pulmonary malformations.

BACKGROUND: Several studies have shown that the congenital pulmonary airway malformation volume ratio is a useful prognosticator of neonatal outcome in prenatally diagnosed lung lesions. However, there remains a lack of consensus on which congenital pulmonary airway malformation volume ratio values have the best predictive value because of operator dependence, inherent changes in lung lesion size throughout gestation, and the widespread use of maternal steroids. OBJECTIVE: This study sought to determine the association between serial congenital pulmonary airway malformation volume ratio measurements and neonatal outcomes among fetuses with lung malformations. STUDY DESIGN: This was a retrospective cohort study of fetuses with a prenatally diagnosed lung malformation managed at 2 major fetal centers from January 2010 to December 2021. Prenatal variables, including prospectively measured congenital pulmonary airway malformation volume ratio measurements (initial, maximum, and final), were analyzed. The results were correlated with 3 outcome measures, namely surgical resection before 30 days of life, a need for supplemental O2 at birth, and endotracheal intubation at birth. Statistical analyses were performed using receiver operating characteristic curve analyses, Welch 2 sample t tests, and multivariable logistic regressions (P<.05). RESULTS: There were 123 fetuses with isolated lung lesions identified. Eight (6.5%) had hydrops. The mean initial congenital pulmonary airway malformation volume ratio was 0.67±0.61 cm2 at 22.9±3.9 weeks' gestation. The mean maximum congenital pulmonary airway malformation volume ratio was 1.08 ± 0.94 cm2 at 27.0 ± 4.0 weeks' gestation. The mean final congenital pulmonary airway malformation volume ratio was 0.58±0.60 cm2 at 33.2±4.1 weeks' gestation. At a mean gestational age at delivery of 38.3±2.6 weeks, 15 (12.2%) underwent neonatal lung resection for symptomatic disease. In a multivariable regression, all 3 congenital pulmonary airway malformation volume ratio measurements showed a significant correlation with neonatal lung resection (P<.001). Optimal congenital pulmonary airway malformation volume ratio cutoffs were established based on an initial congenital pulmonary airway malformation volume ratio of ≥0.8 cm2, maximum congenital pulmonary airway malformation volume ratio of ≥1.5 cm2, and a final congenital pulmonary airway malformation volume ratio of ≥1.3 cm2 with associated areas under the curve of 0.89, 0.97, and 0.93, respectively. The final congenital pulmonary airway malformation volume ratio had the highest specificity for predicting surgical lung resection in the early postnatal period. CONCLUSION: Measuring congenital pulmonary airway malformation volume ratios throughout pregnancy in fetuses with pulmonary malformations has clinical value for prenatal counseling and planning care transition after delivery. Fetuses with a final congenital pulmonary airway malformation volume ratio of more than 1.3 cm2 are likely to require neonatal surgery and therefore should be delivered at tertiary care centers with a neonatal intensive care unit and pediatric surgical expertise.

Potential higher risk of tethered spinal cord in children after prenatal surgery for myelomeningocele: A systematic review and meta-analysis.

INTRODUCTION: We performed a systematic review and meta-analysis on the incidence of secondary tethered spinal cord (TSC) between prenatal and postnatal closure in patients with MMC. The objectives was to understand the incidence of secondary TSC after prenatal surgery for MMC compared to postnatal surgery for MMC. MATERIAL AND METHODS: On May 4, 2023, a systematic search was conducted in Medline, Embase, and the Cochrane Library to gather relevant data. Primary studies focusing on repair type, lesion level, and TSC were included, while non-English or non-Dutch reports, case reports, conference abstracts, editorials, letters, comments, and animal studies were excluded. Two reviewers assessed the included studies for bias risk, following PRISMA guidelines. TSC frequency in MMC closure types was determined, and the relationship between TSC occurrence and closure technique was analyzed using relative risk and Fisher's exact test. Subgroup analysis revealed relative risk differences based on study designs and follow-up periods. A total of ten studies, involving 2,724 patients, were assessed. Among them, 2,293 patients underwent postnatal closure, while 431 received prenatal closure for the MMC defect. In the prenatal closure group, TSC occurred in 21.6% (n = 93), compared to 18.8% (n = 432) in the postnatal closure group. The relative risk (RR) of TSC in patients with prenatal MMC closure versus postnatal MMC closure was 1.145 (95%CI 0.939 to 1.398). Fisher's exact test indicated a statistically non-significant association (p = 0.106) between TSC and closure technique. When considering only RCT and controlled cohort studies, the overall RR for TSC was 1.308 (95%CI 1.007 to 1.698) with a non-significant association (p = .053). For studies focusing on children up until early puberty (maximum 12 years follow-up), the RR for tethering was 1.104 (95%CI 0.876 to 1.391), with a non-significant association (p = 0.409). CONCLUSION AND DISCUSSION: This review found no significant increase in relative risk of TSC between prenatal and postnatal closure in MMC patients, but a trend of increased TSC in the prenatal group. More long-term data on TSC after fetal closure is needed for better counseling and outcomes in MMC.

Development of a simulator for training of fetoscopic myelomeningocele surgery.

OBJECTIVE: To develop a realistic simulation model for laparotomy-assisted fetoscopic spina bifida aperta (SBa) surgery, to be used for training purposes and preoperative planning. METHODS: The predefined general requirement was a realistic model of an exteriorized uterus, allowing all neurosurgical steps of the intervention. The uterus was modelled using ultrasound and MRI images of a 25 weeks' gravid uterus, consisting of flexible polyurethane foam coated with pigmented silicone. The fetal model, contained an opening on the dorsal side for a customizable spinal insert with all the aspects of a SBa, including a cele, placode, and myofascial and skin layer. The model was assessed in a series of validation experiments. RESULTS: Production costs are low, uterus and fetus are reusable. Placental localization and the level and size of the spinal defect are adjustable, enabling case-specific adaptations. All aspects of the simulator were scored close to realistic or higher for both appearance and functional capacities. CONCLUSIONS: This innovative model provides an excellent training opportunity for centers that are starting a fetoscopic SBa repair program. It is the first simulation model with adjustable spinal defect and placental localisation. Further objective validation is required, but the potential for using this model in preoperative planning is promising.

Morbidity in children after fetoscopic endoluminal tracheal occlusion for severe congenital diaphragmatic hernia: Results from a multidisciplinary clinic.

BACKGROUND: Although fetoscopic endoluminal tracheal occlusion (FETO) was recently shown to improve survival in a multicenter, randomized trial of severe congenital diaphragmatic hernia (CDH), morbidity outcomes remain essentially unknown. The purpose of this study was to assess long-term outcomes in children with severe CDH who underwent FETO. METHODS: We conducted a prospective study of severe CDH patients undergoing FETO at an experienced North American center from 2015-2021 (NCT02710968). This group was compared to a cohort of non-FETO CDH patients with severe disease as defined by liver herniation, large defect size, and/or ECMO use. Clinical data were collected through a multidisciplinary CDH clinic. Statistics were performed with t-tests and Chi-squared analyses (p≤0.05). RESULTS: There were 18 FETO and 17 non-FETO patients. ECMO utilization was 56% in the FETO cohort. Despite significantly lower median observed/expected lung-to-head ratio (O/E LHR) in the FETO group, [FETO: 23% (IQR:18-25) vs. non-FETO: 36% (IQR: 28-41), p<0.001], there were comparable survival rates at discharge (FETO: 78% vs. non-FETO: 59%, p = 0.23) and at 5-years (FETO: 67% vs. non-FETO: 59%, p = 0.53) between the two cohorts. At a median follow up of 5.8 years, metrics of pulmonary hypertension, pulmonary morbidity, and gastroesophageal reflux disease improved among patients after FETO. However, most FETO patients remained on bronchodilators/inhaled corticosteroids (58%) and were feeding tube dependent (67%). CONCLUSIONS: These North American data show that prenatal tracheal occlusion, in conjunction with a long-term multidisciplinary CDH clinic, is associated with acceptable long-term survival and morbidity in children after FETO. LEVEL OF EVIDENCE: Level III.

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.

Postnatal care setting and survival after fetoscopic tracheal occlusion for severe congenital diaphragmatic hernia: A systematic review and meta-analysis.

BACKGROUND: Fetoscopic endoluminal tracheal occlusion (FETO) was recently shown to improve postnatal survival in a multicenter, randomized controlled trial of infants with severe congenital diaphragmatic hernia (CDH). However, the external validity of this study remains unclear given a lack of standardization in postnatal management approaches. The purpose of this study was to evaluate the impact of an integrated prenatal and postnatal care setting on survival outcomes in severe CDH after FETO. STUDY DESIGN: A systematic review, meta-analysis, and individual participant analysis of FETO outcomes in severe CDH were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The primary outcome was survival to discharge. Subgroup analyses of patients managed in integrated versus nonintegrated settings were performed to identify predictors of outcome. RESULTS: The review generated five studies (n = 192) for the meta-analysis of FETO versus expectant prenatal management. These data revealed a significant survival benefit after FETO that was restricted to an integrated setting (OR 2.97, 95% Confidence Interval 1.69-4.26). There were nine studies (n = 150) for the individual participant analysis, which showed that FETO managed in an integrated setting had significantly increased survival rates when compared to FETO treated in a nonintegrated setting (70.7% vs. 45.7%, p = 0.003). Multi-level logistic regression identified increased availability of extracorporeal membrane oxygenation (ECMO) as the strongest determinant of postnatal survival (OR=18.8, p = 0.049). CONCLUSION: This systematic review shows that institutional integration of prenatal and postnatal care is associated with the highest overall survival in children with severe CDH. These data highlight the importance of a standardized, multidisciplinary approach, including access to ECMO, as a critical postnatal component in optimizing FETO outcomes in CDH.