Sleep-related breathing disorders in infants with spina bifida repaired prenatally and postnatally.

STUDY OBJECTIVES: Advances in prenatal repair of myelomeningocele (MMC) have improved outcomes involving different organ systems. There is limited data on respiratory outcomes following prenatal surgical repair. We hypothesize there is no difference in respiratory outcomes between spina bifida (SB) patients who have undergone prenatal versus postnatal repair. METHODS: We performed a retrospective study of 46 infants <1 year with SB seen at Children's Hospital Los Angeles from 2004-2022. Demographic data, timing of closure, neonatal course, Chiari II malformation (CIIM), ventriculoperitoneal shunt (VPS), polysomnography (PSG) results, and need for supplemental oxygen were collected. Unpaired t-test and Chi-square Test were used to analyze results. RESULTS: 31/46 had prenatal repair of MMC; average age at repair was 27 weeks post-conception (PCA). Average age at postnatal repair was 37 PCA. There was no difference in age at PSG. There was no difference in CIIM presence (p=0.61). 60% of patients with postnatal repair and 23% in the prenatal group underwent VPS placement (p=0.01).There was no difference in PSG findings between the two groups: CAI (p=0.11), OAHI (p=0.64), average SpO2 baseline (p=0.91), average SpO2 nadir (p=0.17), average PETCO2 baseline (p=0.87), and average PETCO2 maximum (p=0.54). There were no significant differences in the proportion of patients on supplemental O2 (p=0.25), CSA or OSA between groups. CONCLUSIONS: Patients with SB who've undergone closure of neural tube defect have persistent central apneas, obstructive apneas, and significant hypoxemia. There were no differences in the frequency or severity of sleep-disordered breathing in those with prenatal repair versus postnatal repair.

Third-trimester fetoscopic ablation therapy for types II and III vasa previa.

BACKGROUND: Vasa previa is an obstetrical condition in which fetal vessels located near the cervix traverse the fetal membranes unprotected by underlying placenta. Type I vasa previa arises directly from a velamentous cord root, whereas types II and III arise from an accessory lobe or a distal lobe of the same placenta, respectively. Fetoscopic laser ablation for types II and III vasa previa is a novel therapeutic option with benefits that include surgical resolution of the vasa previa, avoidance of prolonged hospitalization, and opportunity for a term vaginal delivery. The potential risks of fetoscopy can be mitigated by delaying laser surgery until a gestational age of 31 to 33 weeks, immediately before anticipated hospitalized surveillance. OBJECTIVE: This study aimed to assess feasibility and outcomes of types II and III vasa previa patients treated via fetoscopic laser ablation in the third trimester. STUDY DESIGN: This is a retrospective study of singleton pregnancies with types II and III vasa previa treated with fetoscopic laser ablation at a gestational age ≥31 weeks at a single center between 2006 and 2022. Pregnancy and newborn outcomes were assessed. Continuous variables are expressed as mean±standard deviation. RESULTS: Of 84 patients referred for vasa previa, 57 did not undergo laser ablation: 19 either had no or resolved vasa previa, 25 had type I vasa previa (laser-contraindicated), and 13 had type II or III vasa previa but declined laser treatment. Of the remaining 27 patients who underwent laser ablation, 7 were excluded (laser performed at <31 weeks and/or twins), leaving 20 study patients. The mean gestational age at fetoscopic laser ablation was 32.0±0.6 weeks, and total operative time was 62.1±19.6 minutes. There were no perioperative complications. All patients had successful occlusion of the vasa previa vessels (1 required a second procedure). All patients were subsequently managed as outpatients. The mean gestational age at delivery was 37.2±1.8 weeks, the mean birthweight was 2795±465 g, and 70% delivered vaginally. Neonatal intensive care unit admission occurred in 3 cases: 1 for respiratory distress syndrome and 2 for hyperbilirubinemia requiring phototherapy. There were no cases of neonatal transfusion, intraventricular hemorrhage, sepsis, patent ductus arteriosus, or death. CONCLUSION: Laser ablation for types II and III vasa previa at 31 to 33 gestational weeks was technically achievable and resulted in favorable outcomes.

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.

Fetoscopic Laser Ablation of Type II Vasa Previa: A Cost Benefit Analysis.

OBJECTIVE: We aimed to compare costs of two strategies for third-trimester type II vasa previa management: (1) fetoscopic laser ablation surgery (FLS) referral and (2) standard management (SM). STUDY DESIGN: A decision analytic model and cost-benefit analysis from a health care perspective were performed. The population included patients with type II vasa previa at approximately 32 weeks. SM entailed 32-week antepartum admission and cesarean at approximately 35 weeks. FLS referral included consultation and possible laser surgery at 32 weeks for willing/eligible candidates. Successful laser surgery allowed the possibility of term vaginal delivery. Outcomes included antepartum admission, preterm birth, cesarean, neonatal transfusion, and death. Sensitivity analyses were performed. RESULTS: In base case analysis, FLS referral was cost saving compared with SM (total cost per patient $65,717.10 vs. 71,628.16). FLS referrals yielded fewer antepartum admissions, cesareans, premature births, neonatal transfusions, and deaths. Eligible referred patients choosing FLS incurred a total cost of $41,702.46, a >40% decrease compared with SM. FLS referral was cost saving in all one-way sensitivity analyses except when antepartum admission costs were low. In threshold analyses, FLS referral was cost saving unless laser surgery cost was >$39,892 (2.75x expected cost), antepartum admission cost for monitoring of vasa previa or ruptured membranes was <$7,455, <11% patients were eligible for laser surgery, and when <12% of eligible patients chose laser surgery. In two-way sensitivity analysis, FLS referral was cost saving except at very high laser surgery costs and extremely low antepartum admission costs. CONCLUSION: Referral for FLS for type II vasa previa was cost saving and improved outcomes compared with SM, despite upfront costs, fetoscopy-related risks, and many patients being ineligible or not opting for surgery after referral. KEY POINTS: · Vasa previa rupture may lead to fetal exsanguination and death.. · Late preterm cesarean is common practice for prenatally diagnosed vasa previa.. · Successful fetoscopic laser ablation for type II vasa previa has been described.. · Laser ablation of vasa previa allows for a safe-term vaginal delivery.. · Referral for laser surgery is cost saving and is associated with improved outcomes..

Subclassification of fetal growth restriction type IIa vs type IIb applied to twin-twin transfusion syndrome.

BACKGROUND: Subclassification of monochorionic twins with selective fetal growth restriction type II into IIa vs IIb has been proposed because of differing neonatal survival outcomes of the fetus with growth restriction after laser surgery based on preoperative Doppler findings in the middle cerebral artery and ductus venosus. There is substantial clinical overlap between selective fetal growth restriction and twin-twin transfusion syndrome. OBJECTIVE: This study aimed to compare donor twin neonatal survival after laser surgery in cases of twin-twin transfusion syndrome with concomitant donor fetal growth restriction type IIa vs IIb. STUDY DESIGN: This was a retrospective study of monochorionic multifetal pregnancies treated with laser surgery for stage III twin-twin transfusion syndrome and concomitant donor twin fetal growth restriction type II at a referral center from 2006 to 2021. Donor fetal growth restriction type II was defined as having an estimated fetal weight <10th percentile with persistent absent and/or reversed end-diastolic velocity in the umbilical artery. Moreover, patients were subclassified as type IIa (having normal middle cerebral artery peak systolic velocities and ductus venosus Doppler waveforms) vs type IIb (having middle cerebral artery peak systolic velocities ≥1.5 multiples of the median and/or ductus venosus with persistent absent or reversed atrial systolic flow). This study compared 30-day neonatal survival of the donor twin by fetal growth restriction type IIa vs IIb using logistic regression to adjust for relevant preoperative covariates (P<.10 in bivariate analysis). RESULTS: Of 919 patients who underwent laser surgery for twin-twin transfusion syndrome, 262 had sstage III donor or donor and recipient twin-twin transfusion syndrome; of these patients, 189 (20.6%) had concomitant donor fetal growth restriction type II. Moreover, 12 patients met the exclusion criteria, yielding 177 patients (19.3%) who composed the study cohort. Patients were subclassified as donor fetal growth restriction type IIa (146 [82%]) vs type IIb (31 [18%]). Donor neonatal survival for fetal growth restriction type IIa vs IIb was 71.2% vs 41.9% (P=.003). Recipient neonatal survival did not differ between the 2 types (P=1.000). Patients classified with twin-twin transfusion syndrome and concomitant donor fetal growth restriction type IIb were 66% less likely to have neonatal survival of the donor after laser surgery (adjusted odds ratio, 0.34; 95% confidence interval, 0.15-0.80; P=.0127). The logistic regression model was adjusted for gestational age at the procedure, estimated fetal weight percent discordance, and nulliparity. The c-statistic was 0.702. CONCLUSION: For patients with stage III twin-twin transfusion syndrome and concurrent donor fetal growth restriction with persistent absent or reversed end-diastolic velocity in the umbilical artery (ie, fetal growth restriction type II), subclassification into fetal growth restriction type IIb based on elevated middle cerebral artery peak systolic velocity and/or abnormal ductus venosus flow in the donor conveyed poorer prognosis. Although donor neonatal survival after laser surgery was lower for patients with stage III twin-twin transfusion syndrome with donor fetal growth restriction type IIb than patients with stage III twin-twin transfusion syndrome with donor fetal growth restriction with type IIa, laser surgery for fetal growth restriction type IIb in the setting of twin-twin transfusion syndrome (as opposed to pure selective fetal growth restriction type IIb) still allows for the possibility of dual survivorship and should be offered with shared decision-making when counseling patients on management options.

Prenatal repair of gastroschisis using partial carbon dioxide insufflation fetoscopy: lessons learned.

We report the long-term outcomes of a case of prenatal gastroschisis repair using a fully percutaneous fetoscopic approach with partial carbon dioxide insufflation. Surgery was performed as an experimental procedure before the scheduled elective birth. The fetal intestines were successfully returned to the abdominal cavity without any fetal or maternal complications. Ultrasonography performed 24 hours later revealed bowel peristalsis and no signs of fetal distress. After 48 hours, partial extrusion of the small bowel was observed, and the fetus was delivered. Gastroschisis repair was immediately performed upon delivery using the EXIT-like procedure as per our institutional protocol. The newborn did not require assisted mechanical ventilation, was discharged at 14 days of age and was then exclusively breastfed. At 3-year follow-up, the patient had no associated gastroschisis-related complications. This is the first case of prenatal repair of gastroschisis, which provides baseline knowledge for future researchers on the potential hurdles and management of prenatal repair.

Multimodal Management of Cervical Insufficiency Complicated by Intra-amniotic Candida albicans Infection.

INTRODUCTION: Bacteria are the most common pathogens implicated in ascending infections in patients with cervical insufficiency. However, Candida albicans is a rare and serious cause of intra-amniotic infection that should be considered on the differential diagnosis. Upon diagnosis following cerclage placement, patients are generally advised to undergo immediate cerclage removal and discontinuation of the pregnancy due to the high risk of maternal and fetal morbidity. However, some patients decline and instead elect to continue the pregnancy with or without treatment. Limited data exist to guide management of these high-risk patients. CASE PRESENTATION: We describe a case of previable intra-amniotic C. albicans infection diagnosed following physical examination-indicated cerclage placement. The patient declined pregnancy termination and subsequently underwent systemic antifungal therapy as well as serial intra-amniotic fluconazole instillations. Fetal blood sampling confirmed transplacental transfer of maternal systemic antifungal therapy. The fetus delivered preterm and without evidence of fungemia, despite persistently positive amniotic fluid cultures. CONCLUSION: In a well-counseled patient with culture-proven intra-amniotic C. albicans infection declining termination of pregnancy, multimodal antifungal therapy in the form of systemic and intra-amniotic fluconazole administration may prevent subsequent fetal or neonatal fungemia and improve postnatal outcomes. KEY POINTS: · Candida is an uncommon cause of intra-amniotic infection in the setting of cervical insufficiency.. · Multimodal antifungal therapy may prevent fetal fungemia related to intra-amniotic Candida infection.. · Fetal blood sampling confirmed transplacental passage of fluconazole after maternal administration..

Advances in Fetal Surgical Repair of Open Spina Bifida.

Spina bifida remains a common congenital anomaly of the central nervous system despite national fortification of foods with folic acid, with a prevalence of 2-4 per 10,000 live births. Prenatal screening for the early detection of this condition provides patients with the opportunity to consider various management options during pregnancy. Prenatal repair of open spina bifida, traditionally performed by the open maternal-fetal surgical approach through hysterotomy, has been shown to improve outcomes for the child, including decreased need for cerebrospinal fluid diversion surgery and improved lower neuromotor function. However, the open maternal-fetal surgical approach is associated with relatively increased risk for the patient and the overall pregnancy, as well as future pregnancies. Recent advances in minimally invasive prenatal repair of open spina bifida through fetoscopy have shown similar benefits for the child but relatively improved outcomes for the pregnant patient and future childbearing.

Neuropathology Evaluation of in Utero Correction of Myelomeningocele and Complications of Late-Onset GBS Infection.

Background: Myelomeningocele (MMC) causes significant morbidity and mortality. Efforts have been directed to correct this defect in utero. The neuropathology literature on antenatally repaired MMC and associated complications in humans is limited. Case report: A 12-day-old female, who underwent prenatal MMC repair via a two-layer closure (dural replacement patch, primary skin closure), was born at 34 weeks' gestation. Her group B streptococcus positive mother received appropriate antepartum prophylactic antibiotics. She remained stable until day 11 of life when she underwent rapid clinical deterioration. Despite aggressive intervention, she expired on day 12. Review of placental pathology showed maternal and fetal inflammatory response. Autopsy revealed Gram-positive cocci and inflammation within the basilar leptomeninges and lumbosacral region. Neural and dermal elements were present within the MMC repair. Conclusion: This case documents integration of the dermal matrix patch to neural elements, adhering the spinal cord to scar tissue, the clinical implications of which remain unclear.

Solomon versus selective fetoscopic laser photocoagulation for twin-twin transfusion syndrome: A systematic review and meta-analysis.

This meta-analysis aims to compare the perinatal outcome of twin-twin transfusion syndrome (TTTS) pregnancies undergoing selective versus vascular equator (Solomon) fetoscopic laser photocoagulation (FLP). We performed a systematic search in PubMed and Web of Science from inception up to 25 July 2021. Studies comparing the Solomon and selective techniques of FLP for treatment of TTTS pregnancies were eligible. Random-effects or fixed-effect models were used to pool standardized mean differences (SMD) and log odds ratio. Seven studies with a total of 1664 TTTS pregnancies (n = 671 undergoing Solomon and n = 993 selective techniques) were included. As compared to the selective FLP, Solomon was associated with a lower risk of recurrent TTTS compared to the selective technique (Log odds ratio [OR]: -1.167; 95% credible interval [CrI]: -2.01, -0.33; p = 0.021; I2 : 67%). In addition, Solomon was significantly associated with a higher risk of placental abruption than the selective technique (Log [OR]: 1.44; 95% CrI: 0.45, 2.47; p = 0.012; I2 : 0.0%). Furthermore, a trend for the higher risk of preterm premature rupture of membranes was observed among those undergoing Solomon (Log [OR]: 0.581; 95% CrI: -0.43, 1.49; p = 0.131; I2 : 17%). As compared to selective FLP, the Solomon technique for TTTS pregnancies is associated with a significantly lower recurrence of TTTS; however, it significantly increases the risk of placental abruption.

Prenatal repair of gastroschisis using partial carbon dioxide insufflation fetoscopy: lessons learned

ABSTRACT We report the long-term outcomes of a case of prenatal gastroschisis repair using a fully percutaneous fetoscopic approach with partial carbon dioxide insufflation. Surgery was performed as an experimental procedure before the scheduled elective birth. The fetal intestines were successfully returned to the abdominal cavity without any fetal or maternal complications. Ultrasonography performed 24 hours later revealed bowel peristalsis and no signs of fetal distress. After 48 hours, partial extrusion of the small bowel was observed, and the fetus was delivered. Gastroschisis repair was immediately performed upon delivery using the EXIT-like procedure as per our institutional protocol. The newborn did not require assisted mechanical ventilation, was discharged at 14 days of age and was then exclusively breastfed. At 3-year follow-up, the patient had no associated gastroschisis-related complications. This is the first case of prenatal repair of gastroschisis, which provides baseline knowledge for future researchers on the potential hurdles and management of prenatal repair.

In utero Treatment of Congenital High Airway Obstruction Syndrome via Fetal Laryngoscopy and EXIT Procedure.

INTRODUCTION: Congenital high airway obstruction syndrome (CHAOS) is a rare condition that can progress to fetal hydrops and demise in utero or at birth unless interventions are undertaken to alleviate the tracheal obstruction. While the ex-utero intrapartum treatment (EXIT) procedure for airway stabilization is technically feasible, abnormal pulmonary development as a result of the antenatal obstructive process may result in severe postnatal respiratory complications. CASE PRESENTATION: We describe a case of CHAOS with secondary hydrops treated in utero at 24 0/7 weeks' gestation by fetoscopic tracheal decompression via laser perforation of the airway obstruction. Interval imaging after the fetoscopic operation demonstrated resolution of the fetal hydrops. Tracheostomy for airway stabilization was performed at the time of the EXIT procedure near term (36 0/7 weeks). The patient underwent tracheal reconstruction and decannulation at 3 years of life. DISCUSSION/CONCLUSION: The primary goal of fetoscopic airway evaluation and intervention is not necessarily to perform definitive stabilization of the airway but rather to achieve sufficient decompression of the trachea to reverse fetal hydrops and salvage pulmonary development. In utero fetoscopic treatment may allow for prolongation of the pregnancy with delivery at or near term via EXIT procedure for definitive neonatal airway stabilization.

Current Status of the Workforce and Training at Fetal Therapy Centers in North America.

INTRODUCTION: We sought to characterize the current workforce and training for fetal intervention procedures at fetal centers in North America. METHODS: An anonymous electronic survey was developed to query the 34 centers in the North American Fetal Treatment Network regarding the demographics and training of their faculty. Telephone surveys were conducted with directors of known fetal intervention fellowships. RESULTS: More than 50% of maternal-fetal medicine (MFM) faculty at fetal centers were female; more than two-thirds of pediatric surgical faculty were male. Most of the training of faculty was undertaken by visiting more experienced centers or having new faculty work with more experienced ones at the same center. Current fetal intervention fellowships appear to achieve levels of competency for intrauterine transfusions and laser therapy for twin-twin transfusion syndrome. Two-thirds of centers stated that they would be able to offer a position to an MFM who completed a formal fellowship in fetal intervention. CONCLUSION: A collaborative effort should be undertaken to establish formal fellowships in fetal medicine and intervention.

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.

Percutaneous/mini-laparotomy fetoscopic repair of open spina bifida: a novel surgical technique.

Open spina bifida is the most common congenital anomaly of the central nervous system compatible with life. Prenatal repair of open spina bifida via open maternal-fetal surgery has been shown to improve postnatal neurologic outcomes, including reducing the need for ventriculoperitoneal shunting and improving lower neuromotor function. Fetoscopic repair of open spina bifida minimizes the maternal risks while providing similar neurosurgical outcomes to the fetus. The following 2 fetoscopic techniques are currently in use: (1) the laparotomy-assisted approach, and (2) the percutaneous approach. The laparotomy-assisted fetoscopic technique appears to be associated with a lesser risk of preterm birth than the percutaneous approach. However, the percutaneous approach avoids laparotomy and uterine exteriorization and is associated with lesser anesthesia risk and improved maternal postsurgical recovery. The purpose of this article was to describe our experience with a modified surgical approach, which we call percutaneous/mini-laparotomy fetoscopy, in which access to the uterus for one of the ports is done via a mini-laparotomy, whereas the other ports are inserted percutaneously. This technique draws on the benefits of both the laparotomy-assisted and the percutaneous techniques while minimizing their drawbacks. This surgical approach may prove invaluable in the prenatal repair of open spina bifida and other complex fetal surgical procedures.

Outcomes of laser surgery for stage I twin-twin transfusion syndrome.

OBJECTIVE: A recent randomized controlled trial (RCT) demonstrated no difference in 6 month survival in expectantly managed stage I twin-twin transfusion syndrome (TTTS) patients and those undergoing immediate laser surgery. We aimed to describe outcomes following immediate laser surgery at a single fetal surgery center. METHODS: A retrospective study of monochorionic diamniotic twins diagnosed with stage I TTTS who underwent laser surgery between 16 and 26 gestational weeks from 2006 to 2019. The primary outcome was 6 month survivorship. Intact survival was also assessed. Secondarily, outcomes were compared to the RCT expectant management group. RESULTS: Of 126 consecutive stage I TTTS patients, 114 (90.5%) met inclusion criteria. Median (range) gestational age at delivery was 34.1 (20.6-39.4) weeks. At 6 months, the proportion of patients with at-least-one survivor in the single-center-laser cohort was 97.4%, with 88.6% dual survivorship. Neurological morbidity outcomes were available in 110 pregnancies (220 fetuses). Severe neurological morbidity occurred in 2.7% (6/220), and 6 month survival without severe neurological morbidity was 90.0%. Outcomes compared favorably with the RCT expectant management group. CONCLUSIONS: Given favorable survival and neurological outcomes, laser surgery is a reasonable treatment option for stage I TTTS at experienced fetal surgery centers. Further study is warranted to optimize treatment strategies.

Amylase concentration and activity in the amniotic fluid of fetal rats with retinoic acid induced myelomeningocele.

BACKGROUND: In utero neurologic injury in myelomeningocele (MMC) occurs via a two-hit process: failed neural tube closure followed by neurodegeneration in utero. Meconium in the amniotic fluid contains pancreatic digestive enzymes and is neurotoxic in rat models of MMC. OBJECTIVES: The objectives of this study were to demonstrate the neurotoxicity of α-amylase and to compare the enzyme concentration and activity in the amniotic fluid of rats with retinoic acid induced MMC to a healthy control population. STUDY DESIGN: Timed pregnant Sprague Dawley rats were gavage fed all-trans retinoic acid (60 mg/kg) in olive oil on gestational day E10 to induce a MMC defect. Control rats received olive oil. Amniotic fluid was collected on embryonic days E15, E17, E19, and E21. The amniotic fluid amylase concentration and relative activity were measured at each gestational age, and levels were compared between the MMC and control groups using Wilcoxon Rank Sum and Kruskal-Wallis tests. In a subset of dams sacrificed on E10.5, neuroepithelial cells were isolated from control embryos and exposed to α-amylase in increasing concentrations. Percentage of cell survival was assessed with CellProfiler software. RESULTS: Amniotic fluid amylase activity for embryonic days E15, E17, E19, and E21 was determined for MMC and control pups. Amylase activity increased significantly from E15 to E21 in both control (p = 3.0 × 10-5) and MMC (p = 1.5 × 10-5) groups. Relative amylase activity was significantly increased in MMC pups compared to controls on E19 (247,792.8 versus 106,263.6; p = .0019) and E21 (772,645.8 versus 481,975.3; p = .021); no difference was detected on E15 (36,646.8 versus 40,179.3; p = .645) or E17 (121,617.5 versus 71,750; p = 1.000). In vitro, amylase demonstrated dose-dependent toxicity to fetal rat neuroepithelial cells. CONCLUSION: Amylase concentration and activity level were higher in the amniotic fluid of rats with retinoic acid induced MMC compared to controls with advancing gestational age. As amylase is toxic to neural epithelial cells, the higher activity of this digestive enzyme in fetuses with MMC may be a contributor to neural tube damage in utero. Future research should focus on amylase and other digestive enzymes in human MMC, as they may serve as potential targets of in utero therapy.

Selective intrauterine growth restriction (SIUGR) type II: proposed subclassification to guide surgical management.

BACKGROUND: Optimal surgical management of monochorionic diamniotic twins complicated by selective intrauterine growth restriction (SIUGR) type II is unknown. Surgical management may involve selective laser photocoagulation of communicating vessels (SLPCV), which offers the possibility of dual twin survivors versus umbilical cord occlusion (UCO) of the SIUGR twin. OBJECTIVE: To identify patient characteristics associated with SIUGR twin survival for those undergoing SLPCV. STUDY DESIGN: All patients studied were those who underwent fetal treatment for SIUGR type II at our center from 2006-2018. SIUGR type II was defined as an estimated fetal weight <10th percentile with persistent absent and/or reversed end diastolic flow in the umbilical artery of the SIUGR twin, in the absence of twin-twin transfusion syndrome. Patients were offered SLPCV versus UCO, and those undergoing SLPCV, patient characteristics associated with 30-day survival of the SIUGR twin were examined using bivariate analysis and multiple logistic regression models. RESULTS: Fifty-four consecutive SIUGR type II patients were treated, 45 via SLPCV and nine via UCO. Of the 45 SLPCV cases, there were 16 (35.6%) with SIUGR twin (and dual) survival. SIUGR twin survival appeared associated with middle cerebral artery (MCA) peak systolic velocity (psv) <1.5 multiples of the median, and forward atrial systolic flow in the ductus venosus (DV). In a post hoc analysis, we subsequently categorized patients as: SIUGR type IIa (N = 32 (71.1%)): normal MCA psv, and normal DV waveform, versus SIUGR type IIb (N = 13 (28.9%)): MCA psv ≥1.5 multiples of the median, and/or DV with absent or reversed atrial systolic flow. Thirty-day survival of the SIUGR twin was 50% for type IIa and 0% for type IIb. CONCLUSION: Over one-third of SIUGR type II patients experienced dual survival after treatment with laser surgery. Normal MCA psv and normal DV waveforms were associated with SIUGR type II survival of the SIUGR twin. Post hoc exploration and subclassification of SIUGR type II patients by preoperative Doppler indices created two groups, one (type IIa) with 50% survival and one (type IIb) with 0% survival of the SIUGR twin after laser surgery. Upon further confirmation, these findings may provide guidance for counseling patients and conducting fetal therapy.